Add shared Icon primitive and controlled glyph vocabulary (Carbon, filled)

docs/IMPLEMENTATION-PLAN.md

@@ -151,7 +151,7 @@ and the companion `visual-specimen.html`.
 
 - Align `src/core/vega-themes.ts`: chart `Config` per theme + a categorical
   `range.category` palette (clone `carbon-design-system/carbon-charts` for the
-  sequence — see Architecture 09 §7).
+  sequence — see Architecture 09 §8).
 
 **Tests**
 

docs/architecture/09-visual-design.md

@@ -171,7 +171,176 @@ UI by swapping one set of values. Borrowed from Carbon's layering model:
 
 ---
 
-## 5. Charts (`src/core/vega-themes.ts`)
+## 5. Iconography
+
+> Geometry and the accessibility floor are set elsewhere: icons keep Carbon's
+> rounded 2px geometry and are exempt from `--radius` (§3.4), and every icon-only
+> control carries an accessible name with meaning never resting on colour alone
+> ([arch 10 §5–6](10-interaction-and-feedback.md)). This section is the **usage**
+> contract — _when_ a thing earns an icon, and how the set stays coherent.
+
+**Stance: balanced, label-first.** Astrolabe is a tool its user returns to often
+— the one context where GOV.UK concedes icons earn their place: _"Icons can be
+more useful in case working systems, where users are familiar with the interface
+and return to it frequently … In most cases it's still helpful to include a
+visible text label alongside any icons"_ (GOV.UK, `styles/images`). So we are
+neither icon-rich (Carbon's default density) nor icon-austere (GOV.UK's
+public-service default): the default is **text**; an icon is added only when it
+does real work, and usually _alongside_ the text, not instead of it.
+
+### 5.1 The icon-vs-text decision
+
+Apply in order:
+
+1. **Default to text.** If a label alone is clear, ship the label. An icon that
+   only decorates fails principle 1 (Considered) and invites the ambiguity GOV.UK
+   warns of — _"people can understand a single icon to mean different things."_
+2. **Add an icon when it does a job** — one of: speeds scanning of a list/row read
+   repeatedly (dataset marker), signals status/type at a glance (draft dot), or
+   affords a high-frequency action (delete). Carbon's rule holds: _"employ icons
+   sparingly and strategically … to reduce cognitive load."_
+3. **Pair icon + text by default.** In any labelled control, menu item, or row,
+   the icon rides _alongside_ its text — recognition support (NN/g #6), not a
+   replacement for the word.
+4. **Icon-only is the exception, and a closed set.** Permitted only for the
+   **universal set** (§5.2) — glyphs whose meaning is unambiguous and which recur
+   everywhere. A new icon-only control is never created ad-hoc; admitting one to
+   the set is a contract change, not a per-component decision.
+
+| Form        | When                                                     | Accessible name                                   |
+| ----------- | -------------------------------------------------------- | ------------------------------------------------- |
+| Text only   | The default. Label is clear on its own.                  | The visible text                                  |
+| Icon + text | Icon aids scanning/status; text stays the primary label. | The visible text; icon `aria-hidden` (decorative) |
+| Icon only   | Universal-set glyph in a space-constrained control.      | `aria-label` on the control (APG button pattern)  |
+
+> Accessible-name mechanics (APG button pattern): a control's name comes from its
+> text content, or from `aria-label`/`aria-labelledby` when there is none. So an
+> icon **beside visible text** is `aria-hidden` (the text names it — avoiding the
+> duplicate screen-reader readout GOV.UK flags); an icon **alone** needs an
+> `aria-label`.
+
+### 5.2 The icon vocabulary (controlled set)
+
+One icon = one meaning, **app-wide** — GOV.UK: _"Do not use a single icon to
+represent more than one thing."_ The vocabulary is a **uniqueness ledger**, not a
+hall of fame: every glyph is registered here so the same meaning always reuses its
+glyph and no glyph is ever repurposed — even a one-off gets a row, so it can't be
+reused for something else later. The registry lives in code at
+[`src/app/components/Icon.tsx`](../../src/app/components/Icon.tsx) (the `IconName`
+union + `GLYPHS` map); this table is its prose mirror. Glyphs are traced from
+Carbon and drawn `fill: currentColor`.
+
+**Core set** — recurring, cross-surface:
+
+| Meaning              | Carbon glyph    | Form                  | Surfaces                                          |
+| -------------------- | --------------- | --------------------- | ------------------------------------------------- |
+| Close / dismiss      | `Close` (✕)     | icon-only ⭐          | `ModalShell`, `Toaster`                           |
+| Theme → dark         | `Asleep` (moon) | icon-only ⭐          | `ThemeToggle` (shown when light)                  |
+| Theme → light        | `Light` (sun)   | icon-only ⭐          | `ThemeToggle` (shown when dark)                   |
+| References a dataset | `DataTable`     | icon + text           | Library row marker, Linked-datasets list          |
+| Add / create-new     | `Add`           | icon + text           | Library "Create New Snippet", Datasets "New …"    |
+| Delete               | `TrashCan`      | icon-only ⭐ (danger) | Library row delete¹ — text "Delete" in the panel² |
+| Unpublished draft    | (CSS dot)       | status-glyph          | Library row (paired with a hidden label)          |
+
+**Status set** — Carbon's **filled** notification glyphs, one per severity. Unlike
+the outline UI set, these are coloured **by status** (not by surrounding text) and
+are a deliberate _filled_ sub-family. They add a **redundant, non-colour severity
+channel** (WCAG 1.4.1): meaning never rests on the bar colour alone, and the
+triangle shape-codes warning apart from the round error/success/info — so severity
+survives colour-blindness. Used wherever a status is signalled (toasts today; inline
+notifications/validation as they arrive):
+
+| Meaning | Carbon glyph         | Colour                  | Surfaces                                    |
+| ------- | -------------------- | ----------------------- | ------------------------------------------- |
+| Error   | `ErrorFilled`        | `--support-error`       | `Toaster` (error)                           |
+| Warning | `WarningAltFilled` ▲ | `--support-warning-fg`³ | `Toaster` (warning), Chart Builder warnings |
+| Success | `CheckmarkFilled`    | `--support-success`     | `Toaster` (success)                         |
+| Info    | `InformationFilled`  | `--support-info`        | `Toaster` (info)                            |
+
+**Scoped set** — registered (glyph reserved) but single-surface and **not yet
+implemented**:
+
+| Meaning          | Carbon glyph       | Form        | Surface / note                                        |
+| ---------------- | ------------------ | ----------- | ----------------------------------------------------- |
+| Swap / transpose | `ArrowsHorizontal` | icon + text | Chart Builder "Swap X/Y" — one button; icon is polish |
+
+⭐ = **icon-only set**: close + theme (truly universal), plus **delete** as a
+deliberate destructive-row exception — a dense, repeated list action where a label
+would cost more than it gives. ✕ means **close only**; delete is `TrashCan`, never
+✕ (that collision is exactly what one-glyph-one-meaning forbids).
+
+¹ Row delete is hover/focus-revealed and reddens on hover/focus (arch 10 — reveal &
+destructive-intent rules). ² "Duplicate" and "Delete" in the detail panel stay
+**text** (label-first; lower frequency, not a dense row). ³ The raw warning yellow
+fails contrast on light surfaces, so the warning glyph uses `--support-warning-fg`
+(darkened amber; the yellow `--toast-accent` stays on the decorative border).
+
+### 5.3 Size
+
+Carbon's icon scale, paired to our type. The tokens are live in
+`styles/tokens.css`; the `Icon` component's `size` prop selects one:
+
+| Token       | Size | Pairs with                     | Use                                         |
+| ----------- | ---- | ------------------------------ | ------------------------------------------- |
+| `--icon-sm` | 16px | 14px body (`--font-size-base`) | Default — inline with text, row markers     |
+| `--icon-md` | 20px | 16px text                      | Slightly emphasised controls (theme toggle) |
+| `--icon-lg` | 24px | —                              | When a larger icon is genuinely needed      |
+| `--icon-xl` | 32px | —                              | Rare; large display only                    |
+
+- _"16px and 20px icons are optimized to feel balanced when paired with 14pt and
+  16pt IBM Plex"_ (Carbon) → **16px (`sm`) is our default**, since body is 14px.
+- Use an icon **at its scale** — don't rescale a 16px glyph to 11px or 13px (the
+  old 11px dataset glyph and 18px toggle were the drift this fixed).
+- Carbon's glyphs are drawn on a 32-unit grid with a built-in stroke weight per
+  size; because we render them **filled** (see §5.4) there is no stroke token to
+  set — sizing the SVG is all that's needed.
+
+### 5.4 Style, colour & alignment
+
+- **Geometry & fill:** Carbon's rounded 2px corners, per §3.4. Carbon's UI icons
+  are **filled** shapes (`fill: currentColor`) that read as outlines — _not_
+  `stroke`-drawn. Our `Icon` primitive draws fill; the size classes set width and
+  height only. (The two original hand-rolls used `stroke`; tracing the real Carbon
+  glyphs moved us to fill.)
+- **Colour:** monochrome, one colour, **inherits `currentColor`** so it matches
+  its text — Carbon: _"match your icon colour with your text colour … don't use
+  different colours for text and icons"_; must pass contrast. Two sanctioned
+  recolours: **destructive intent** (delete reddens to `--support-error` on
+  hover/focus — arch 10) and the **status sub-family** (§5.2), coloured by severity
+  rather than by text — those are graphical status objects (WCAG 3:1), and warning
+  uses the darkened `--support-warning-fg` so it clears contrast on light surfaces.
+- **Alignment:** centre-align with adjacent text — never baseline-align (Carbon).
+- **Sourcing:** Carbon is **not a dependency**; we transcribe the glyph's SVG
+  geometry into `Icon.tsx`'s `GLYPHS` map (Carbon's third-party rule, inverted — a
+  new glyph must be _"visually balanced"_ with the set). Match an existing icon's
+  32-grid when adding one.
+- **Hit area:** the interactive target (the button), not the glyph, owns the click
+  size — our 32/40px buttons already clear comfortable targets; never shrink the
+  target down to the icon.
+
+### 5.5 Current state
+
+The contract is implemented across the M1–M4 surfaces:
+
+- **Infrastructure:** `--icon-*` tokens in `styles/tokens.css`; a shared
+  [`Icon`](../../src/app/components/Icon.tsx) primitive + the `GLYPHS` registry as
+  the single source of truth. Components import `Icon`, never inline an SVG.
+- **Core set live:** `Close` (ModalShell, Toaster — replacing the bare ✕/×),
+  `Asleep`/`Light` (ThemeToggle, now on-scale), `DataTable` (library row + linked
+  list, replacing the 11px cylinder), `TrashCan` (row delete), `Add` (both
+  "create-new" buttons). The draft dot is unchanged.
+- **Status set live:** the four filled glyphs (`ErrorFilled` / `WarningAltFilled` /
+  `CheckmarkFilled` / `InformationFilled`) in `Toaster`, coloured by kind; the
+  Chart-Builder warnings reuse `WarningAltFilled` (replacing the old ⚠ character).
+- **Deferred (scoped set):** only the Chart-Builder `ArrowsHorizontal` (swap-axes) —
+  registered, not built; a one-button polish revisited with the next Chart-Builder
+  pass.
+
+No open status thread remains — the status-glyph question is settled here.
+
+---
+
+## 6. Charts (`src/core/vega-themes.ts`)
 
 The chart `Config` is themed to match the app, per theme:
 
@@ -185,7 +354,7 @@ The chart `Config` is themed to match the app, per theme:
 
 ---
 
-## 6. Implementation map
+## 7. Implementation map
 
 | Artifact                                         | Role                                                  |
 | ------------------------------------------------ | ----------------------------------------------------- |
@@ -212,7 +381,7 @@ keeps the specimen finite, honest, and worth trusting.
 
 ---
 
-## 7. Inspiration sources — where to look for more
+## 8. Inspiration sources — where to look for more
 
 We treat IBM/Carbon as inspiration, so we mine its **source repos**, not the live
 doc sites. The sites (`carbondesignsystem.com`, `ibm.com/design/language`) are
@@ -221,12 +390,12 @@ Convention: clone under `/Users/oleh/code/reference/` with
 `git clone --depth 1 https://github.com/carbon-design-system/<repo>.git`.
 
 | Need                                                                                                           | Repo                      | Where it lives                                                                                                                                                                                                                                                                                                                                      |
-| -------------------------------------------------------------------------------------------------------------- | ------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
+| -------------------------------------------------------------------------------------------------------------- | ------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
-| **Principles / the "why"** (philosophy, 2x grid, color rationale, type, motion, icon geometry)                 | `design-language-website` | `src/pages/`: `philosophy/principles.mdx`, `2x-grid.mdx`, `color.mdx`, `typography/*.mdx`, `animation/overview.mdx`, `iconography/ui-icons/design.mdx` (~1.4 GB clone — image-heavy; the MDX is what we want) |
+| **Principles / the "why"** (philosophy, 2x grid, color rationale, type, motion, icon geometry)                 | `design-language-website` | `src/pages/`: `philosophy/principles.mdx`, `2x-grid.mdx`, `color.mdx`, `typography/*.mdx`, `animation/overview.mdx`, `iconography/ui-icons/{design,usage}.mdx` (~1.4 GB clone — image-heavy; the MDX is what we want). Icon **usage** rules (§5) also draw on `carbon-website/src/pages/elements/icons/usage.mdx` + GOV.UK `styles/images/index.md` |
 | **Token values** (gray/blue ramps, type scale, font families, motion durations/easings, theme role→value maps) | `carbon`                  | `packages/colors/src/colors.ts`, `packages/type/src/{scale,fontFamily,fontWeight}.ts`, `packages/motion/src/index.ts`, `packages/themes/src/{white,g100}.ts`                                                                                                                                                                                        |
 | **Component-level usage guidance**                                                                             | `carbon-website`          | `src/pages/**/*.mdx`                                                                                                                                                                                                                                                                                                                                |
 | **Data-viz categorical chart palette** (for `vega-themes.ts` `range.category`)                                 | `carbon-charts`           | cloned in M1.5 → `packages/core/scss/_color-palette.scss` (the `'14'` pairing, white + g100); token→hex resolved against `carbon` `packages/colors/src/colors.ts`                                                                                                                                                                                   |
 
-> The decisions we made _from_ these sources are captured above (§1–6) and in the
+> The decisions we made _from_ these sources are captured above (§1–7) and in the
 > specimen, so we don't need to re-derive them — only return to the repos to extend
 > the research (e.g. the chart palette, or a component pattern we haven't tackled).

docs/architecture/10-interaction-and-feedback.md

@@ -110,6 +110,11 @@ states are part of the feature, not an afterthought (Carbon empty-states, GOV.UK
 - **Wording** (NN/g #9, GOV.UK, Carbon content): plain language, **no error codes in the
   user-facing line**, second person, name what stopped in the title, one or two sentences
   in the body, never flippant.
+- **Status carries a glyph, not only colour** (arch 09 §5.2 status set; Carbon notification
+  taxonomy). Error/warning/success/info surfaces (toasts, inline warnings) lead with the
+  **filled status icon**, coloured by severity — a redundant non-colour channel so severity
+  reads under colour-blindness (WCAG 1.4.1), with the triangle shape-coding warning apart
+  from the round error/success/info. Colour + icon + title together; never colour alone.
 
 ## 4. Recovery & data-safety contract
 
@@ -229,9 +234,9 @@ Not features to add later — the baseline every surface is built on.
 
 - **Reduced motion is honored globally.** Animations/transitions are neutralized under
   `prefers-reduced-motion` (`styles/base.css`); never gate meaning on motion.
-- **Colour is never the sole signal** (WCAG; Carbon status pattern). Pair it with a label,
+- **Colour is never the sole signal** (WCAG 1.4.1; Carbon status pattern). Pair it with a
-  icon, shape, or text — a red toast border also has a title and an `alert` role; the
+  label, icon, shape, or text — a toast carries a title, an `alert`/`status` role, **and a
-  draft dot has a `title`/`aria-label`.
+  filled status glyph** coloured by severity (§3); the draft dot has a `title`/`aria-label`.
 - **Every control is labelled.** Icon-only buttons, toggles, and fields carry accessible
   names so assistive tech can announce them.
 - **A binary toggle exposes its state, not just its action.** A theme/on-off control is a

docs/architecture/visual-specimen.html

@@ -995,6 +995,45 @@
         </div>
       </section>
 
+      <!-- ICONS -->
+      <section>
+        <h2>Iconography — Carbon glyphs, fill: currentColor</h2>
+        <div class="cap" style="margin-bottom: var(--space-5)">
+          The controlled vocabulary (arch 09 §5). One glyph per meaning; 16px default, paired
+          to 14px body. Filled (not stroked) — they inherit text colour and theme.
+        </div>
+        <div class="row" style="gap: var(--space-7); flex-wrap: wrap; align-items: flex-start">
+          <span style="display: inline-flex; flex-direction: column; align-items: center; gap: var(--space-2); color: var(--text-secondary)">
+            <svg width="16" height="16" viewBox="0 0 32 32" style="fill: currentColor"><polygon points="17.4141 16 24 9.4141 22.5859 8 16 14.5859 9.4143 8 8 9.4141 14.5859 16 8 22.5859 9.4143 24 16 17.4141 22.5859 24 24 22.5859 17.4141 16"/></svg>
+            <span class="cap">close</span>
+          </span>
+          <span style="display: inline-flex; flex-direction: column; align-items: center; gap: var(--space-2); color: var(--text-secondary)">
+            <svg width="16" height="16" viewBox="0 0 32 32" style="fill: currentColor"><path d="M13.5025,5.4136A15.0755,15.0755,0,0,0,25.096,23.6082a11.1134,11.1134,0,0,1-7.9749,3.3893c-.1385,0-.2782.0051-.4178,0A11.0944,11.0944,0,0,1,13.5025,5.4136M14.98,3a1.0024,1.0024,0,0,0-.1746.0156A13.0959,13.0959,0,0,0,16.63,28.9973c.1641.006.3282,0,.4909,0a13.0724,13.0724,0,0,0,10.702-5.5556,1.0094,1.0094,0,0,0-.7833-1.5644A13.08,13.08,0,0,1,15.8892,4.38,1.0149,1.0149,0,0,0,14.98,3Z"/></svg>
+            <span class="cap">moon</span>
+          </span>
+          <span style="display: inline-flex; flex-direction: column; align-items: center; gap: var(--space-2); color: var(--text-secondary)">
+            <svg width="16" height="16" viewBox="0 0 32 32" style="fill: currentColor"><rect x="15" y="2" width="2" height="5"/><rect x="21.6675" y="6.8536" width="4.958" height="1.9998" transform="translate(1.5191 19.3744) rotate(-45)"/><rect x="25" y="15" width="5" height="2"/><rect x="23.1466" y="21.6675" width="1.9998" height="4.958" transform="translate(-10.0018 24.1465) rotate(-45)"/><rect x="15" y="25" width="2" height="5"/><rect x="5.3745" y="23.1466" width="4.958" height="1.9998" transform="translate(-14.7739 12.6256) rotate(-45)"/><rect x="2" y="15" width="5" height="2"/><rect x="6.8536" y="5.3745" width="1.9998" height="4.958" transform="translate(-3.253 7.8535) rotate(-45)"/><path d="M16,12a4,4,0,1,1-4,4,4.0045,4.0045,0,0,1,4-4m0-2a6,6,0,1,0,6,6,6,6,0,0,0-6-6Z"/></svg>
+            <span class="cap">sun</span>
+          </span>
+          <span style="display: inline-flex; flex-direction: column; align-items: center; gap: var(--space-2); color: var(--text-secondary)">
+            <svg width="16" height="16" viewBox="0 0 32 32" style="fill: currentColor"><rect x="8" y="18" width="4" height="2"/><rect x="14" y="18" width="4" height="2"/><rect x="8" y="14" width="4" height="2"/><rect x="14" y="22" width="4" height="2"/><rect x="20" y="14" width="4" height="2"/><rect x="20" y="22" width="4" height="2"/><path d="M27,3H5A2.0025,2.0025,0,0,0,3,5V27a2.0025,2.0025,0,0,0,2,2H27a2.0025,2.0025,0,0,0,2-2V5A2.0025,2.0025,0,0,0,27,3Zm0,2,0,4H5V5ZM5,27V11H27l0,16Z"/></svg>
+            <span class="cap">dataset</span>
+          </span>
+          <span style="display: inline-flex; flex-direction: column; align-items: center; gap: var(--space-2); color: var(--text-secondary)">
+            <svg width="16" height="16" viewBox="0 0 32 32" style="fill: currentColor"><polygon points="17,15 17,8 15,8 15,15 8,15 8,17 15,17 15,24 17,24 17,17 24,17 24,15"/></svg>
+            <span class="cap">add</span>
+          </span>
+          <span style="display: inline-flex; flex-direction: column; align-items: center; gap: var(--space-2); color: var(--text-secondary)">
+            <svg width="16" height="16" viewBox="0 0 32 32" style="fill: currentColor"><rect x="12" y="12" width="2" height="12"/><rect x="18" y="12" width="2" height="12"/><path d="M4,6V8H6V28a2,2,0,0,0,2,2H24a2,2,0,0,0,2-2V8h2V6ZM8,28V8H24V28Z"/><rect x="12" y="2" width="8" height="2"/></svg>
+            <span class="cap">delete</span>
+          </span>
+        </div>
+        <div class="cap" style="margin-top: var(--space-6)">
+          In context: icon + text is the default; icon-only is the universal/destructive
+          exception. ✕ means close only — delete is the trash glyph.
+        </div>
+      </section>
+
       <!-- TABS + STATUS -->
       <section>
         <h2>Tabs · status · tags</h2>
@@ -1010,19 +1049,8 @@
           <span class="tag-pill"><span class="dot draft"></span> Draft changes</span>
           <span class="tag-pill"><span class="dot published"></span> Published</span>
           <span class="tag-pill">
-            <svg
+            <svg width="16" height="16" viewBox="0 0 32 32" style="fill: currentColor">
-              width="14"
+              <rect x="8" y="18" width="4" height="2" /><rect x="14" y="18" width="4" height="2" /><rect x="8" y="14" width="4" height="2" /><rect x="14" y="22" width="4" height="2" /><rect x="20" y="14" width="4" height="2" /><rect x="20" y="22" width="4" height="2" /><path d="M27,3H5A2.0025,2.0025,0,0,0,3,5V27a2.0025,2.0025,0,0,0,2,2H27a2.0025,2.0025,0,0,0,2-2V5A2.0025,2.0025,0,0,0,27,3Zm0,2,0,4H5V5ZM5,27V11H27l0,16Z" />
-              height="14"
-              viewBox="0 0 24 24"
-              fill="none"
-              stroke="currentColor"
-              stroke-width="2"
-              stroke-linecap="round"
-              stroke-linejoin="round"
-            >
-              <ellipse cx="12" cy="6" rx="8" ry="3" />
-              <path d="M4 6v12c0 1.7 3.6 3 8 3s8-1.3 8-3V6" />
-              <path d="M4 12c0 1.7 3.6 3 8 3s8-1.3 8-3" />
             </svg>
             2 datasets
           </span>
@@ -1125,11 +1153,27 @@
       <!-- TOASTS -->
       <section>
         <h2>Toasts</h2>
+        <div class="cap" style="margin-bottom: var(--space-4)">
+          Filled status glyph + colour + text — a non-colour severity channel (arch 09 §5.2 /
+          10 §3). The triangle shape-codes warning apart from the round error/success/info.
+        </div>
         <div class="stack" style="max-width: 360px">
-          <div class="toast info">Snippet duplicated.</div>
+          <div class="toast info">
-          <div class="toast success">Published “Quarterly revenue”.</div>
+            <svg width="16" height="16" viewBox="0 0 32 32" style="fill: currentColor; flex: none; color: var(--support-info)"><path d="M16,2A14,14,0,1,0,30,16,14,14,0,0,0,16,2Zm0,6a1.5,1.5,0,1,1-1.5,1.5A1.5,1.5,0,0,1,16,8Zm4,16.125H12v-2.25h2.875v-5.75H13v-2.25h4.125v8H20Z"/></svg>
-          <div class="toast warning">Snippet storage is 82% full.</div>
+            Snippet duplicated.
-          <div class="toast error">Could not save — storage is full.</div>
+          </div>
+          <div class="toast success">
+            <svg width="16" height="16" viewBox="0 0 32 32" style="fill: currentColor; flex: none; color: var(--support-success)"><path d="M16,2A14,14,0,1,0,30,16,14,14,0,0,0,16,2ZM14,21.5908l-5-5L10.5906,15,14,18.4092,21.41,11l1.5957,1.5859Z"/></svg>
+            Published “Quarterly revenue”.
+          </div>
+          <div class="toast warning">
+            <svg width="16" height="16" viewBox="0 0 32 32" style="fill: currentColor; flex: none; color: var(--support-warning-fg, #8a6d00)"><path d="M16.002,6.1714h-.004L4.6487,27.9966,4.6506,28H27.3494l.0019-.0034ZM14.875,12h2.25v9h-2.25ZM16,26a1.5,1.5,0,1,1,1.5-1.5A1.5,1.5,0,0,1,16,26Z"/></svg>
+            Snippet storage is 82% full.
+          </div>
+          <div class="toast error">
+            <svg width="16" height="16" viewBox="0 0 32 32" style="fill: currentColor; flex: none; color: var(--support-error)"><path d="M16,2A13.914,13.914,0,0,0,2,16,13.914,13.914,0,0,0,16,30,13.914,13.914,0,0,0,30,16,13.914,13.914,0,0,0,16,2Zm5.4449,21L9,10.5557,10.5557,9,23,21.4448Z"/></svg>
+            Could not save — storage is full.
+          </div>
         </div>
       </section>
 

src/app/components/ChartBuilderModal.module.css

@@ -214,14 +214,20 @@
 }
 
 .warning {
+  display: flex;
+  align-items: flex-start;
+  gap: var(--space-2);
   font-size: 12px;
   line-height: 1.4;
   color: var(--text-secondary);
 }
 
-.warning::before {
+/* Filled status-warning glyph (arch 09 §5.2), in the contrast-safe amber. Replaces
-  content: '⚠ ';
+   the old ⚠ text character so the warning matches the toast status family. */
-  color: var(--support-warning, var(--text-secondary));
+.warningIcon {
+  flex: none;
+  margin-top: 1px;
+  color: var(--support-warning-fg);
 }
 
 /* Explains the disabled Create action (contract 10: a disabled control must say

src/app/components/ChartBuilderModal.tsx

@@ -53,6 +53,7 @@ import {
   useChartBuilderStore,
 } from '../stores/ChartBuilderStore';
 import { SegmentedControl, type SegmentedOption } from './SegmentedControl';
+import { Icon } from './Icon';
 import styles from './ChartBuilderModal.module.css';
 
 const RENDER_DEBOUNCE_MS = 300;
@@ -460,7 +461,8 @@ export function ChartBuilderModal() {
           <ul className={styles.warnings}>
             {warnings.map((w) => (
               <li key={w.message} className={styles.warning}>
-                {w.message}
+                <Icon name="status-warning" className={styles.warningIcon} />
+                <span>{w.message}</span>
               </li>
             ))}
           </ul>

src/app/components/DatasetsModal.module.css

@@ -17,6 +17,10 @@
 
 .newButton {
   flex: 0 0 auto;
+  display: inline-flex;
+  align-items: center;
+  justify-content: center;
+  gap: var(--space-2);
   margin: var(--space-4);
   height: 40px;
   padding: 0 var(--space-5);

src/app/components/DatasetsModal.tsx

@@ -22,6 +22,7 @@ import { notify } from '../stores/NotificationStore';
 import { selectSelectedDataset, useDatasetStore, byModifiedDesc } from '../stores/DatasetStore';
 import { useSnippetStore } from '../stores/SnippetStore';
 import { SegmentedControl, type SegmentedOption } from './SegmentedControl';
+import { Icon } from './Icon';
 import styles from './DatasetsModal.module.css';
 
 /** Display label for a format (spec §05 → List item: JSON / CSV / TSV / TopoJSON). */
@@ -76,7 +77,7 @@ export function DatasetsModal() {
     <div className={styles.manager}>
       <div className={styles.listPane}>
         <button type="button" className={styles.newButton} onClick={handleNew}>
-          + New Dataset
+          <Icon name="add" /> New Dataset
         </button>
         <ul className={styles.list}>
           {ordered.length === 0 && (

src/app/components/Icon.module.css

@@ -0,0 +1,30 @@
+/* Shared icon primitive (arch 09 §5). Icons are fill: currentColor SVG, so they
+   inherit the surrounding text colour and theme automatically. The size classes
+   map to the Carbon scale tokens; the glyph keeps its own rounded geometry and is
+   exempt from --radius (square chrome applies to chrome, not icons). */
+.icon {
+  display: inline-block;
+  flex: 0 0 auto;
+  fill: currentColor;
+  vertical-align: middle;
+}
+
+.sm {
+  width: var(--icon-sm);
+  height: var(--icon-sm);
+}
+
+.md {
+  width: var(--icon-md);
+  height: var(--icon-md);
+}
+
+.lg {
+  width: var(--icon-lg);
+  height: var(--icon-lg);
+}
+
+.xl {
+  width: var(--icon-xl);
+  height: var(--icon-xl);
+}

src/app/components/Icon.test.tsx

@@ -0,0 +1,57 @@
+import { afterEach, beforeEach, describe, expect, test } from 'vitest';
+import { act } from 'react';
+import { createRoot, type Root } from 'react-dom/client';
+import { Icon } from './Icon';
+
+(globalThis as { IS_REACT_ACT_ENVIRONMENT?: boolean }).IS_REACT_ACT_ENVIRONMENT = true;
+
+let container: HTMLDivElement;
+let root: Root;
+
+beforeEach(() => {
+  container = document.createElement('div');
+  document.body.appendChild(container);
+  root = createRoot(container);
+});
+
+afterEach(() => {
+  act(() => root.unmount());
+  container.remove();
+});
+
+function render(node: React.ReactNode) {
+  act(() => root.render(node));
+  const svg = container.querySelector('svg');
+  if (!svg) throw new Error('no <svg> rendered');
+  return svg;
+}
+
+describe('Icon', () => {
+  test('renders an SVG on the Carbon 32-grid, decorative and unfocusable', () => {
+    const svg = render(<Icon name="close" />);
+    expect(svg.getAttribute('viewBox')).toBe('0 0 32 32');
+    // Decorative by default: the enclosing control carries the accessible name.
+    expect(svg.getAttribute('aria-hidden')).toBe('true');
+    expect(svg.getAttribute('focusable')).toBe('false');
+  });
+
+  test('each name draws a distinct glyph from the registry', () => {
+    // close is a single polygon; delete (TrashCan) is rects + a path; dataset
+    // (DataTable) is six cells + a path. Distinct geometry ⇒ distinct meaning.
+    expect(render(<Icon name="close" />).querySelector('polygon')).not.toBeNull();
+    const del = render(<Icon name="delete" />);
+    expect(del.querySelectorAll('rect').length).toBe(3);
+    expect(del.querySelector('path')).not.toBeNull();
+    expect(render(<Icon name="dataset" />).querySelectorAll('rect').length).toBe(6);
+  });
+
+  test('size maps to a single, changeable class token', () => {
+    const sm = render(<Icon name="add" />); // default
+    const smClass = sm.getAttribute('class') ?? '';
+    const md = render(<Icon name="add" size="md" />);
+    const mdClass = md.getAttribute('class') ?? '';
+    // Whatever the CSS-module hashing, the two sizes must resolve to different
+    // class strings so the 16/20/24/32 scale is actually applied, not ignored.
+    expect(smClass).not.toBe(mdClass);
+  });
+});

src/app/components/Icon.tsx

@@ -0,0 +1,142 @@
+/**
+ * Icon — the shared icon primitive and controlled vocabulary (arch 09 §5).
+ *
+ * Astrolabe is label-first: an icon is added only when it does real work, usually
+ * alongside text (arch 09 §5.1). This module is the single source of truth for the
+ * icon set — one glyph per meaning, app-wide (§5.2). Adding an icon means adding a
+ * `IconName` + a registry entry here, never inlining an SVG in a component.
+ *
+ * The glyphs are traced from IBM Carbon's icon set (32×32 grid, fill-based — they
+ * read as outlines but are filled shapes). Carbon is inspiration, not a dependency.
+ * Every glyph draws with `fill: currentColor`, so it inherits its text colour and
+ * themes for free.
+ *
+ * Icons are decorative by default (`aria-hidden`): the control around them carries
+ * the accessible name (text label, or an `aria-label` on an icon-only button — APG
+ * button pattern). Never rely on an icon alone to name a control.
+ */
+
+import type { ReactNode } from 'react';
+import styles from './Icon.module.css';
+
+/** The controlled icon vocabulary (arch 09 §5.2). One entry = one meaning. */
+export type IconName =
+  | 'close' // close / dismiss (universal, icon-only)
+  | 'moon' // theme: switch to dark (universal, icon-only)
+  | 'sun' // theme: switch to light (universal, icon-only)
+  | 'dataset' // "references a dataset" — Carbon DataTable
+  | 'delete' // delete — Carbon TrashCan
+  | 'add' // add / create-new — Carbon Add
+  // Status sub-family (arch 09 §5.2) — Carbon's FILLED notification glyphs, coloured
+  // by status (not text). A redundant non-colour severity channel (WCAG 1.4.1): the
+  // triangle shape-codes warning apart from the round error/success/info.
+  | 'status-error' // Carbon ErrorFilled
+  | 'status-warning' // Carbon WarningAltFilled (triangle)
+  | 'status-success' // Carbon CheckmarkFilled
+  | 'status-info'; // Carbon InformationFilled
+
+/** Carbon icon scale (arch 09 §5.3). 16px (sm) is the default, paired to 14px body. */
+export type IconSize = 'sm' | 'md' | 'lg' | 'xl';
+
+/** Inner SVG geometry per glyph, on Carbon's 0 0 32 32 grid. fill comes from CSS. */
+const GLYPHS: Record<IconName, ReactNode> = {
+  close: (
+    <polygon points="17.4141 16 24 9.4141 22.5859 8 16 14.5859 9.4143 8 8 9.4141 14.5859 16 8 22.5859 9.4143 24 16 17.4141 22.5859 24 24 22.5859 17.4141 16" />
+  ),
+  add: <polygon points="17,15 17,8 15,8 15,15 8,15 8,17 15,17 15,24 17,24 17,17 24,17 24,15" />,
+  delete: (
+    <>
+      <rect x="12" y="12" width="2" height="12" />
+      <rect x="18" y="12" width="2" height="12" />
+      <path d="M4,6V8H6V28a2,2,0,0,0,2,2H24a2,2,0,0,0,2-2V8h2V6ZM8,28V8H24V28Z" />
+      <rect x="12" y="2" width="8" height="2" />
+    </>
+  ),
+  dataset: (
+    <>
+      <rect x="8" y="18" width="4" height="2" />
+      <rect x="14" y="18" width="4" height="2" />
+      <rect x="8" y="14" width="4" height="2" />
+      <rect x="14" y="22" width="4" height="2" />
+      <rect x="20" y="14" width="4" height="2" />
+      <rect x="20" y="22" width="4" height="2" />
+      <path d="M27,3H5A2.0025,2.0025,0,0,0,3,5V27a2.0025,2.0025,0,0,0,2,2H27a2.0025,2.0025,0,0,0,2-2V5A2.0025,2.0025,0,0,0,27,3Zm0,2,0,4H5V5ZM5,27V11H27l0,16Z" />
+    </>
+  ),
+  moon: (
+    <path d="M13.5025,5.4136A15.0755,15.0755,0,0,0,25.096,23.6082a11.1134,11.1134,0,0,1-7.9749,3.3893c-.1385,0-.2782.0051-.4178,0A11.0944,11.0944,0,0,1,13.5025,5.4136M14.98,3a1.0024,1.0024,0,0,0-.1746.0156A13.0959,13.0959,0,0,0,16.63,28.9973c.1641.006.3282,0,.4909,0a13.0724,13.0724,0,0,0,10.702-5.5556,1.0094,1.0094,0,0,0-.7833-1.5644A13.08,13.08,0,0,1,15.8892,4.38,1.0149,1.0149,0,0,0,14.98,3Z" />
+  ),
+  sun: (
+    <>
+      <rect x="15" y="2" width="2" height="5" />
+      <rect
+        x="21.6675"
+        y="6.8536"
+        width="4.958"
+        height="1.9998"
+        transform="translate(1.5191 19.3744) rotate(-45)"
+      />
+      <rect x="25" y="15" width="5" height="2" />
+      <rect
+        x="23.1466"
+        y="21.6675"
+        width="1.9998"
+        height="4.958"
+        transform="translate(-10.0018 24.1465) rotate(-45)"
+      />
+      <rect x="15" y="25" width="2" height="5" />
+      <rect
+        x="5.3745"
+        y="23.1466"
+        width="4.958"
+        height="1.9998"
+        transform="translate(-14.7739 12.6256) rotate(-45)"
+      />
+      <rect x="2" y="15" width="5" height="2" />
+      <rect
+        x="6.8536"
+        y="5.3745"
+        width="1.9998"
+        height="4.958"
+        transform="translate(-3.253 7.8535) rotate(-45)"
+      />
+      <path d="M16,12a4,4,0,1,1-4,4,4.0045,4.0045,0,0,1,4-4m0-2a6,6,0,1,0,6,6,6,6,0,0,0-6-6Z" />
+    </>
+  ),
+  // Filled status glyphs: the symbol is a winding-rule knockout in the solid shape,
+  // so it shows the surface colour through (Carbon's filled notification family).
+  'status-error': (
+    <path d="M16,2A13.914,13.914,0,0,0,2,16,13.914,13.914,0,0,0,16,30,13.914,13.914,0,0,0,30,16,13.914,13.914,0,0,0,16,2Zm5.4449,21L9,10.5557,10.5557,9,23,21.4448Z" />
+  ),
+  'status-warning': (
+    <path d="M16.002,6.1714h-.004L4.6487,27.9966,4.6506,28H27.3494l.0019-.0034ZM14.875,12h2.25v9h-2.25ZM16,26a1.5,1.5,0,1,1,1.5-1.5A1.5,1.5,0,0,1,16,26Z" />
+  ),
+  'status-success': (
+    <path d="M16,2A14,14,0,1,0,30,16,14,14,0,0,0,16,2ZM14,21.5908l-5-5L10.5906,15,14,18.4092,21.41,11l1.5957,1.5859Z" />
+  ),
+  'status-info': (
+    <path d="M16,2A14,14,0,1,0,30,16,14,14,0,0,0,16,2Zm0,6a1.5,1.5,0,1,1-1.5,1.5A1.5,1.5,0,0,1,16,8Zm4,16.125H12v-2.25h2.875v-5.75H13v-2.25h4.125v8H20Z" />
+  ),
+};
+
+export interface IconProps {
+  name: IconName;
+  /** Carbon scale; defaults to `sm` (16px) — the body-text default. */
+  size?: IconSize;
+  /** Extra class for layout-level overrides (margins, colour). */
+  className?: string;
+}
+
+export function Icon({ name, size = 'sm', className }: IconProps) {
+  return (
+    <svg
+      className={`${styles.icon} ${styles[size]}${className ? ` ${className}` : ''}`}
+      viewBox="0 0 32 32"
+      // Decorative: the enclosing control names itself (arch 09 §5.1).
+      aria-hidden="true"
+      focusable={false}
+    >
+      {GLYPHS[name]}
+    </svg>
+  );
+}

src/app/components/ModalShell.tsx

@@ -16,6 +16,7 @@ import { useAppStore } from '../stores/AppStore';
 import { getModalConfig, getModalTitle } from '../modals/modal-registry';
 import { closeModal } from '../modals/ModalCoordinator';
 import { useFocusTrap } from '../hooks/useFocusTrap';
+import { Icon } from './Icon';
 import styles from './ModalShell.module.css';
 
 export function ModalShell() {
@@ -69,7 +70,7 @@ export function ModalShell() {
             aria-label="Close"
             onClick={() => void closeModal()}
           >
-            ×
+            <Icon name="close" />
           </button>
         </header>
         <div className={styles.body}>

src/app/components/ThemeToggle.tsx

@@ -13,45 +13,9 @@
  */
 
 import { useAppStore } from '../stores/AppStore';
+import { Icon } from './Icon';
 import styles from './ThemeToggle.module.css';
 
-function MoonIcon() {
-  return (
-    <svg
-      width="18"
-      height="18"
-      viewBox="0 0 24 24"
-      fill="none"
-      stroke="currentColor"
-      strokeWidth="2"
-      strokeLinecap="round"
-      strokeLinejoin="round"
-      aria-hidden="true"
-    >
-      <path d="M21 12.8A9 9 0 1 1 11.2 3a7 7 0 0 0 9.8 9.8z" />
-    </svg>
-  );
-}
-
-function SunIcon() {
-  return (
-    <svg
-      width="18"
-      height="18"
-      viewBox="0 0 24 24"
-      fill="none"
-      stroke="currentColor"
-      strokeWidth="2"
-      strokeLinecap="round"
-      strokeLinejoin="round"
-      aria-hidden="true"
-    >
-      <circle cx="12" cy="12" r="4.5" />
-      <path d="M12 2v2M12 20v2M4.9 4.9l1.4 1.4M17.7 17.7l1.4 1.4M2 12h2M20 12h2M4.9 19.1l1.4-1.4M17.7 6.3l1.4-1.4" />
-    </svg>
-  );
-}
-
 export function ThemeToggle() {
   const uiTheme = useAppStore((s) => s.uiTheme);
   const toggleTheme = useAppStore((s) => s.toggleTheme);
@@ -69,7 +33,7 @@ export function ThemeToggle() {
       aria-label="Dark theme"
       title={`Switch to ${target} theme`}
     >
-      {uiTheme === 'dark' ? <SunIcon /> : <MoonIcon />}
+      {uiTheme === 'dark' ? <Icon name="sun" size="md" /> : <Icon name="moon" size="md" />}
     </button>
   );
 }

src/app/components/Toaster.module.css

@@ -47,6 +47,18 @@
   --toast-accent: var(--support-info);
 }
 
+/* Leading status glyph (arch 09 §5.2): coloured by kind, top-aligned with the
+   title. The accent IS the icon colour, except warning, whose raw yellow fails
+   contrast on the light surface — it uses the darkened fg token. */
+.statusIcon {
+  flex: none;
+  margin-top: 1px;
+  color: var(--toast-accent);
+}
+.warning .statusIcon {
+  color: var(--support-warning-fg);
+}
+
 @keyframes toast-in {
   from {
     opacity: 0;

src/app/components/Toaster.test.tsx

@@ -0,0 +1,51 @@
+import { afterEach, beforeEach, describe, expect, test } from 'vitest';
+import { act } from 'react';
+import { createRoot, type Root } from 'react-dom/client';
+import { useNotificationStore, type NotificationKind } from '../stores/NotificationStore';
+import { Toaster } from './Toaster';
+
+(globalThis as { IS_REACT_ACT_ENVIRONMENT?: boolean }).IS_REACT_ACT_ENVIRONMENT = true;
+
+let container: HTMLDivElement;
+let root: Root;
+
+beforeEach(() => {
+  useNotificationStore.getState().clear();
+  container = document.createElement('div');
+  document.body.appendChild(container);
+  root = createRoot(container);
+});
+
+afterEach(() => {
+  act(() => root.unmount());
+  container.remove();
+  useNotificationStore.getState().clear();
+});
+
+const KINDS: NotificationKind[] = ['error', 'warning', 'success', 'info'];
+
+describe('Toaster status glyphs', () => {
+  // The point of the status icon is a non-colour severity channel (WCAG 1.4.1) — so
+  // every kind must render a leading glyph, not lean on the border colour alone.
+  test.each(KINDS)('a %s toast renders a leading status glyph', (kind) => {
+    act(() => {
+      useNotificationStore.getState().notify({ kind, title: `${kind} title`, message: 'body' });
+      root.render(<Toaster />);
+    });
+    const toast = container.querySelector('[role="alert"], [role="status"]');
+    expect(toast).not.toBeNull();
+    // The status glyph is a direct-child <svg> of the toast (the close button's svg
+    // is nested inside the button, so :scope > svg isolates the status icon).
+    expect(toast!.querySelector(':scope > svg')).not.toBeNull();
+  });
+
+  test('error and warning are assertive; success and info are polite', () => {
+    act(() => {
+      useNotificationStore.getState().notify({ kind: 'error', title: 'e', message: 'b' });
+      useNotificationStore.getState().notify({ kind: 'success', title: 's', message: 'b' });
+      root.render(<Toaster />);
+    });
+    expect(container.querySelector('[role="alert"]')).not.toBeNull();
+    expect(container.querySelector('[role="status"]')).not.toBeNull();
+  });
+});

src/app/components/Toaster.tsx

@@ -16,6 +16,7 @@ import {
   type Notification,
   type NotificationKind,
 } from '../stores/NotificationStore';
+import { Icon, type IconName } from './Icon';
 import styles from './Toaster.module.css';
 
 /** Auto-dismiss delay for the non-critical kinds (ms). Errors/warnings persist. */
@@ -36,6 +37,15 @@ const KIND_CLASS: Record<NotificationKind, string> = {
   info: styles.info,
 };
 
+/** Filled status glyph per kind (arch 09 §5.2) — a non-colour severity channel,
+ *  decorative (the title names the toast); coloured by kind in the CSS. */
+const KIND_ICON: Record<NotificationKind, IconName> = {
+  error: 'status-error',
+  warning: 'status-warning',
+  success: 'status-success',
+  info: 'status-info',
+};
+
 function Toast({ notification }: { notification: Notification }) {
   const dismiss = useNotificationStore((s) => s.dismiss);
   const { id, kind, title, message, detail } = notification;
@@ -54,6 +64,7 @@ function Toast({ notification }: { notification: Notification }) {
       // Errors/warnings interrupt assistive tech (assertive); the rest are polite.
       role={kind === 'error' || kind === 'warning' ? 'alert' : 'status'}
     >
+      <Icon name={KIND_ICON[kind]} size="md" className={styles.statusIcon} />
       <div className={styles.body}>
         <p className={styles.title}>{title}</p>
         <p className={styles.message}>{message}</p>
@@ -71,7 +82,7 @@ function Toast({ notification }: { notification: Notification }) {
         aria-label="Dismiss notification"
         onClick={() => dismiss(id)}
       >
-        ✕
+        <Icon name="close" />
       </button>
     </div>
   );

src/core/vega-themes.ts

@@ -1,5 +1,5 @@
 /**
- * Vega-Lite chart config per UI theme (docs/architecture/05 §3, 09 §5).
+ * Vega-Lite chart config per UI theme (docs/architecture/05 §3, 09 §6).
  *
  * Portable core: a Vega-Lite `Config` styles every chart globally so charts
  * visually belong to the app rather than looking like stock Vega-Lite. This is

styles/tokens.css

@@ -25,6 +25,13 @@
   --space-8: 48px;
   --space-9: 64px;
 
+  /* Iconography — Carbon icon scale (arch 09 §5.3). Icons are SVG drawn with
+     fill: currentColor; 16px is the default, paired to 14px body text. */
+  --icon-sm: 16px;
+  --icon-md: 20px;
+  --icon-lg: 24px;
+  --icon-xl: 32px;
+
   /* Shape — square chrome (icons keep their own rounded geometry) */
   --radius: 0px;
   --border-width: 1px;
@@ -42,6 +49,9 @@
   --support-error: #da1e28;
   --support-success: #198038;
   --support-warning: #f1c21b;
+  /* Warning foreground: the raw yellow fails contrast on light surfaces, so status
+     glyphs/text use a darkened amber. Dark theme keeps the yellow (legible on dark). */
+  --support-warning-fg: #8a6d00;
   --support-info: #0043ce;
   --on-status: #ffffff;
 
@@ -74,6 +84,7 @@
   --support-error: #fa4d56;
   --support-success: #42be65;
   --support-warning: #f1c21b;
+  --support-warning-fg: #f1c21b;
   --support-info: #78a9ff;
   --on-status: #161616;
 }