Add snippet-library search, sort, empty states, storage monitor (M6, §02/§09D)

src/app/infrastructure/ux-prefs.test.ts

@@ -2,8 +2,10 @@ import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest';
 import {
   loadPanelLayout,
   loadPaneVisibility,
+  loadSnippetSort,
   savePanelLayout,
   savePaneVisibility,
+  saveSnippetSort,
 } from './ux-prefs';
 
 const KEY = 'astrolabe:ux-prefs';
@@ -98,3 +100,33 @@ describe('ux-prefs · paneVisibility', () => {
     expect(stored.paneVisibility.editor).toBe(false);
   });
 });
+
+describe('ux-prefs · snippetSort', () => {
+  beforeEach(() => vi.stubGlobal('localStorage', makeStorageStub()));
+  afterEach(() => vi.unstubAllGlobals());
+
+  it('defaults to Modified, descending when nothing is stored', () => {
+    expect(loadSnippetSort()).toEqual({ by: 'modified', order: 'desc' });
+  });
+
+  it('round-trips a stored sort', () => {
+    saveSnippetSort({ by: 'name', order: 'asc' });
+    expect(loadSnippetSort()).toEqual({ by: 'name', order: 'asc' });
+  });
+
+  it('falls back to defaults for invalid stored values', () => {
+    localStorage.setItem(KEY, JSON.stringify({ snippetSort: { by: 'bogus', order: 'sideways' } }));
+    expect(loadSnippetSort()).toEqual({ by: 'modified', order: 'desc' });
+  });
+
+  it('preserves panelLayout when writing the sort (separate keys)', () => {
+    savePanelLayout({ libraryWidth: 280 });
+    saveSnippetSort({ by: 'size', order: 'desc' });
+    const stored = JSON.parse(localStorage.getItem(KEY)!) as {
+      panelLayout: { libraryWidth: number };
+      snippetSort: { by: string; order: string };
+    };
+    expect(stored.panelLayout.libraryWidth).toBe(280);
+    expect(stored.snippetSort).toEqual({ by: 'size', order: 'desc' });
+  });
+});

src/app/infrastructure/ux-prefs.ts

@@ -4,7 +4,7 @@
  * These preferences persist **separately** from UserSettings so they can change
  * frequently (a drag emits many width updates) without rewriting the settings
  * record. Its own key, `astrolabe:ux-prefs`, holds the snippet sort preference
- * (lands with M5/M6) and the panel layout (per-pane widths + visibility).
+ * (spec §02 → Sort) and the panel layout (per-pane widths + visibility).
  *
  * This slice persists the panel **widths** and per-pane **visibility** (spec §01A).
  * Read-with-fallback + write-through merge, the same contract as the settings
@@ -15,6 +15,13 @@
  * `localStorage`; everything else goes through these typed functions.
  */
 
+import {
+  DEFAULT_SORT_BY,
+  DEFAULT_SORT_ORDER,
+  type SortBy,
+  type SortOrder,
+} from '@core/snippet-sort';
+
 const KEY = 'astrolabe:ux-prefs';
 
 /** Per-pane widths (px). Optional — a missing field falls back to its default. */
@@ -30,9 +37,16 @@ export interface PaneVisibilityPref {
   preview?: boolean;
 }
 
+/** The persisted library sort (spec §02 → Sort; persists across sessions). */
+export interface SnippetSortPref {
+  by: SortBy;
+  order: SortOrder;
+}
+
 interface StoredPrefs {
   panelLayout?: PanelLayout;
   paneVisibility?: PaneVisibilityPref;
+  snippetSort?: Partial<SnippetSortPref>;
   [k: string]: unknown;
 }
 
@@ -106,3 +120,29 @@ export function savePaneVisibility(visibility: PaneVisibilityPref): void {
   const current = readRaw();
   writeRaw({ ...current, paneVisibility: { ...current.paneVisibility, ...visibility } });
 }
+
+/** Guards against junk in storage — only the known sort fields survive. */
+function sortBy(v: unknown): SortBy | undefined {
+  return v === 'modified' || v === 'created' || v === 'name' || v === 'size' ? v : undefined;
+}
+function sortOrder(v: unknown): SortOrder | undefined {
+  return v === 'asc' || v === 'desc' ? v : undefined;
+}
+
+/**
+ * The persisted library sort, falling back to the spec default (Modified, desc)
+ * for anything missing or invalid in storage.
+ */
+export function loadSnippetSort(): SnippetSortPref {
+  const stored = readRaw().snippetSort ?? {};
+  return {
+    by: sortBy(stored.by) ?? DEFAULT_SORT_BY,
+    order: sortOrder(stored.order) ?? DEFAULT_SORT_ORDER,
+  };
+}
+
+/** Persist the library sort, preserving every other key already in the record. */
+export function saveSnippetSort(sort: SnippetSortPref): void {
+  const current = readRaw();
+  writeRaw({ ...current, snippetSort: { ...current.snippetSort, ...sort } });
+}