Eng-council: alignment checks from sweep findings + metrics baseline

.claude/skills/alignment/SKILL.md

@@ -40,6 +40,10 @@ Review all changes in scope. If changes span multiple patterns below, apply all
    over-engineering from iterative development — dead code, try/catch around internal calls
    that can't throw, abstraction layers wrapping a single implementation. Proceed with caution;
    ask if unsure.
+   - **Export hygiene**: a symbol is exported only if another module imports it. Symbols used
+     only within their module (including `as const` arrays that exist to derive a type) stay
+     unexported — `export type` the type, not its source array. Verify with Grep before
+     exporting "for future use"; the future caller can add the export.
 
 5. **Styles and UI**: When altering CSS or layout, follow or generalize existing patterns
    (CSS Modules + design tokens in `styles/tokens.css`) rather than writing from scratch. Don't
@@ -128,6 +132,9 @@ Update relevant docs if the feature is significant:
 If `package.json` changed:
 
 - Flag each new dependency; explain what it does and why it's needed.
+- Every package imported directly in `src/` must be declared in `dependencies` — never rely
+  on a transitive install (it can vanish or drift on any lockfile churn). Declaring a package
+  the bundle already carries adds no weight.
 - Could a small custom implementation avoid it? Note the trade-off.
 - Prefer dependencies that solve genuinely hard problems (parsing, rendering) over those that
   save boilerplate.