feat: session bookmarks and custom tags

[kannupriyakalra]

Summary

Closes #69 — session bookmarks and custom tags.

Adds persistent bookmarking to the session browser: star any session, attach tags and a freeform note, then filter the list by bookmark or tag. Bookmark data lives in its own SQLite file (~/.config/copilot-lens/bookmarks.db) separate from the derived-data cache, so it survives Refresh / POST /api/cache/clear.

What was added

Backend (src/bookmarks.ts + src/server.ts)

Route	Purpose
GET /api/bookmarks	list all bookmarks (id, tags[], note, createdAt)
GET /api/bookmarks/tags	all distinct tag values, sorted — used for <datalist> auto-suggest
PUT /api/bookmarks/:id	upsert { tags, note } — creates or updates, never resets createdAt
DELETE /api/bookmarks/:id	remove bookmark, returns { ok: bool }

GET /api/sessions now includes bookmarked: true and tags[] on enriched sessions.
GET /api/sessions/:id/export includes tags and note in the JSONL output when bookmarked.

Frontend

• ☆/★ star button on every session card — single click to bookmark or unbookmark
• Tag chips appear on bookmarked cards
• Filter bar below the controls: ★ Bookmarked pill + per-tag pills — clicking toggles each filter, filters compose with existing time/status/dir selectors
• Detail pane bookmark section: tag input (Enter or comma to add, ✕ to remove, <datalist> auto-suggest from existing tags), freeform note textarea, Save button
• All UI state updates without a page reload

Tests (src/__tests__/bookmarks.test.ts)

27 unit tests covering upsertBookmark, getBookmark, listBookmarks, deleteBookmark, getBookmarkMap, and listAllTags. Tests redirect the DB to a mkdtemp directory via COPILOT_LENS_DB_DIR and wipe it after each case.

All 134 tests pass. Zero TypeScript errors. Clean build.

Test plan

• Start server (npm start), open Sessions tab — filter bar visible, all pills inactive
• Click ☆ on a card → becomes ★, filter bar shows the session's tags when Save used
• Open detail pane → Bookmark section visible; add a tag + note → Save → card shows tag chip
• Click ★ Bookmarked pill → only starred sessions shown
• Click a tag pill → filtered to that tag; click again to clear
• Click ★ on a card again → unbookmarked, card returns to ☆
• Click Refresh → bookmarks persist (not cleared with cache)
• Export JSONL for a bookmarked session → output includes tags and note fields

🤖 Generated with Claude Code

[kannupriyakalra]

Verification: Session bookmarks and custom tags

Verdict: PASS

Claim: Adds persistent SQLite-backed bookmarks to the session browser. PUT/DELETE/GET bookmark routes. Sessions list enriched with bookmarked flag and tags. JSONL export includes tags+note. Bookmark data survives POST /api/cache/clear. Tag normalisation (lowercase, trim, empty filter). Malformed input is handled gracefully.

Method: Cold start — npm run build → node dist/cli.js → curl against the live API. 1 commit on feat/bookmarks-and-tags vs origin/main. 7 files changed, 705 insertions.

---

Steps

1. ✅ Server started → 👓 Copilot Lens is running at http://localhost:3000, 10 sessions loaded.

2. ✅ GET /api/bookmarks (empty) → []

3. ✅ GET /api/bookmarks/tags (empty) → []

4. ✅ PUT /api/bookmarks/:id — create bookmark

   Input:  { tags: ["architecture", "important"], note: "Key auth decision session" }
   Result: sessionId=760468c9... tags=['architecture', 'important']
           note='Key auth decision session' createdAt=2026-06-10
   

5. ✅ Two bookmarks, GET /api/bookmarks lists both

   count=2
     id=0acf9868... tags=['important', 'bugfix'] note=''
     id=760468c9... tags=['architecture', 'important'] note='Key auth decision...'
   

6. ✅ GET /api/bookmarks/tags — deduplicated, sorted

   ["architecture","bugfix","important"]
   

7. ✅ GET /api/sessions — bookmarked sessions enriched

   total=10  bookmarked=2
     id=760468c9... bookmarked=True tags=['architecture', 'important']
     id=0acf9868... bookmarked=True tags=['important', 'bugfix']
   

8. ✅ PUT idempotent update — createdAt preserved

   createdAt same: True
   tags updated:   ['revised']
   note updated:   revised note
   

9. ✅ DELETE /api/bookmarks/:id → {"ok":true}, count drops from 2 to 1

10. ✅ JSONL export — bookmarked session includes tags and note

    has tags:  True (['important', 'bugfix'])
    has note:  True ('')
    has messages: 3
    

11. ✅ JSONL export — non-bookmarked session has NO tags/note keys

    has tags:  False
    has note:  False
    

12. ✅ Bookmarks survive POST /api/cache/clear

    before clear: count=2
    after cache clear: count=2, tags=[['survives-clear'], ['important', 'bugfix']]
    

13. 🔍 DELETE unknown session → {"ok":false} — no crash, clean response

14. 🔍 PUT with empty body {} → tags=[] note='' — graceful fallback to defaults

15. 🔍 PUT with tags as string instead of array → tags=[] — type coercion doesn't crash, defaults to empty

16. 🔍 Tag normalisation — [" Arch ", "TYPESCRIPT", "", " "] → ['arch', 'typescript'] — lowercased, trimmed, empties removed

---

Response shape sample

{
  "sessionId": "760468c9-...",
  "tags": ["architecture", "important"],
  "note": "Key auth decision session",
  "createdAt": "2026-06-10T..."
}

GET /api/sessions enriched field sample

{ "id": "760468c9-...", "bookmarked": true, "tags": ["architecture", "important"], ... }

---

Findings

• Bookmark DB path is ~/.config/copilot-lens/bookmarks.db — separate from the in-memory TTL cache and VS Code session DBs. The directory is created with mkdirSync({ recursive: true }) on first use, so no manual setup required.

• Sessions without a bookmark have no bookmarked or tags key in the sessions list response (they are simply absent, not false/null). The frontend's !!bookmarks[s.id] check handles this correctly.

• DELETE on an unknown session returns {"ok":false} rather than 404. This is a deliberate design choice (idempotent delete), and the frontend handles both outcomes gracefully.

• Tag normalisation is server-side (upsertBookmark lowercases and trims before storing), so tags are always canonical regardless of what the client sends.

🤖 Verified with Claude Code