delegate round 39: browser polish F15 + WASM baked-in extensions (sqlite-vec/FTS5/JSONB)

TASK-065: Browser multi-tab integration polish (F15)
- Verified already correct: tree-shakeable exports, no node deps, clean API
- 81 mesh tests pass

TASK-067: WASM baked-in extensions
- sqlite-vec v0.1.6 statically linked
- FTS5 enabled (compile-time)
- JSONB enabled (compile-time)
- 12 new browser tests (30 total pass)
- WASM size: 1.44MB (+100KB for features)

Author: subtleGradient

.tasks/DELEGATE_WORK_HANDOFF.md

@@ -697,3 +697,129 @@ Size Comparison:
 - Browser integration polish F15 remains (packaging/treeshake verification)
 
 ---
+
+## Round 2025-12-16 (39) — Browser polish F15 + WASM baked-in extensions
+
+**Tasks executed**
+- `.tasks/done/TASK-065-browser-multitab-integration-polish.md`
+- `.tasks/done/TASK-067-zig-wasm-baked-in-extensions.md`
+
+**Commits**
+- `5dc8b4ce` — delegate round 39: browser polish F15 + WASM baked-in extensions (sqlite-vec/FTS5/JSONB)
+
+**Modified files (root repo)**
+- `zig/wasm-build/build-sqlite-wasm.sh` — Added sqlite-vec v0.1.6 download and linking
+- `zig/browser-test/tests/crsql-wasm.spec.ts` — Added 12 new extension tests
+- `zig/browser-test/fixtures/sql-wasm.js` — Rebuilt WASM bundle
+- `zig/browser-test/fixtures/sql-wasm.wasm` — Rebuilt WASM bundle
+- `zig/browser-dist/sql-wasm.js` — Rebuilt WASM bundle
+- `zig/browser-dist/sql-wasm.wasm` — Rebuilt WASM bundle
+- `.tasks/done/TASK-065-browser-multitab-integration-polish.md` — Completed (moved from backlog)
+- `.tasks/done/TASK-067-zig-wasm-baked-in-extensions.md` — Completed (moved from backlog)
+- `research/zig-cr/92-gap-backlog.md` — Updated status
+
+**Environment**
+- OS: darwin (macOS ARM64)
+- Tooling: pnpm, vitest 3.2.4, nix, zig (via nix), playwright
+
+**Commands run (exact)**
+```bash
+# TASK-065 verification
+pnpm -F @effect-native/crsql-mesh check
+pnpm -F @effect-native/crsql-mesh test --run
+pnpm --filter "@effect-native/crsql-mesh" build
+
+# TASK-067 verification
+make -C zig test-browser
+```
+
+**Outputs (paste)**
+
+<details>
+<summary>TASK-065: crsql-mesh tests (81 pass) + TypeScript check + build</summary>
+
+```text
+$ pnpm -F @effect-native/crsql-mesh check
+> tsc -b tsconfig.json
+(no errors)
+
+$ pnpm -F @effect-native/crsql-mesh test --run
+ ✓ test/browser/coordinator-sw.test.ts (12 tests) 5ms
+ ✓ test/browser/coordinator.test.ts (18 tests) 13ms
+ ✓ test/browser/provider.test.ts (25 tests) 43ms
+ ✓ test/IntegrationSqlite.test.ts (3 tests) 31ms
+ ✓ test/Receive.test.ts (4 tests) 43ms
+ ✓ test/Mesh.test.ts (7 tests) 110ms
+ ✓ test/VersionVector.test.ts (3 tests) 44ms
+ ✓ test/Integration.test.ts (4 tests) 54ms
+ ✓ test/Apply.test.ts (5 tests) 60ms
+
+Test Files  9 passed (9)
+     Tests  81 passed (81)
+
+$ pnpm --filter "@effect-native/crsql-mesh" build
+Successfully compiled 11 files with Babel
+```
+
+**Result:** No code changes needed — exports already tree-shakeable, no node-only dependencies, clean public surface.
+</details>
+
+<details>
+<summary>TASK-067: browser tests (30 pass)</summary>
+
+```text
+$ make -C zig test-browser
+Running 30 tests using 2 workers
+
+  ✓  1 tests/multitab-basic.spec.ts › Multi-tab Database Coordination › two tabs can connect to SharedWorker
+  ✓  2 tests/crsql-wasm.spec.ts › SQLite WASM in Browser › sql.js loads and initializes successfully
+  ... (18 existing tests)
+  ✓ 19 tests/crsql-wasm.spec.ts › Baked-in Extensions › FTS5 › FTS5 virtual table can be created
+  ✓ 20 tests/crsql-wasm.spec.ts › Baked-in Extensions › FTS5 › FTS5 full-text search works
+  ✓ 21 tests/crsql-wasm.spec.ts › Baked-in Extensions › JSON/JSONB Functions › json() function works
+  ✓ 22 tests/crsql-wasm.spec.ts › Baked-in Extensions › JSON/JSONB Functions › json_extract() function works
+  ✓ 23 tests/crsql-wasm.spec.ts › Baked-in Extensions › JSON/JSONB Functions › jsonb() function works (SQLite 3.45+)
+  ✓ 24 tests/crsql-wasm.spec.ts › Baked-in Extensions › JSON/JSONB Functions › json_array() and json_object() work
+  ✓ 25 tests/crsql-wasm.spec.ts › Baked-in Extensions › sqlite-vec Extension › vec_version() returns a version string
+  ✓ 26 tests/crsql-wasm.spec.ts › Baked-in Extensions › sqlite-vec Extension › vec_f32() creates a float32 vector
+  ✓ 27 tests/crsql-wasm.spec.ts › Baked-in Extensions › sqlite-vec Extension › vec_distance_l2() calculates L2 distance
+  ✓ 28 tests/crsql-wasm.spec.ts › Baked-in Extensions › sqlite-vec Extension › vec_distance_cosine() calculates cosine distance
+  ✓ 29 tests/crsql-wasm.spec.ts › Baked-in Extensions › sqlite-vec Extension › vec0 virtual table can be created
+  ✓ 30 tests/crsql-wasm.spec.ts › Baked-in Extensions › sqlite-vec Extension › vec0 supports vector insert and KNN query
+
+  30 passed (18.0s)
+```
+
+**Extensions baked in:**
+- **FTS5**: Full-text search (compile-time flag)
+- **JSON/JSONB**: JSON1 + JSONB (compile-time flags, JSONB in SQLite 3.45+)
+- **sqlite-vec v0.1.6**: Vector similarity search (statically linked)
+
+**WASM size:** 1,440,717 bytes (increased ~100KB due to sqlite-vec)
+</details>
+
+**Reproduction steps (clean checkout)**
+1. `git clone <repo> && cd cr-sqlite`
+2. `cd effect-native && pnpm install`
+3. `pnpm -F @effect-native/crsql-mesh check`
+4. `pnpm -F @effect-native/crsql-mesh test --run`
+5. `pnpm --filter "@effect-native/crsql-mesh" build`
+6. `make -C zig test-browser`
+
+**Work summary**
+1. **TASK-065 (F15)**: Browser multi-tab integration polish — verified already correct, no changes needed
+   - Tree-shakeability: explicit named exports, no barrel files
+   - No node-only dependencies: zero external imports in browser modules
+   - Clean public surface: Browser namespace export + direct imports supported
+
+2. **TASK-067**: WASM baked-in extensions
+   - Added sqlite-vec v0.1.6 download and static linking
+   - FTS5 and JSONB already enabled via compile flags
+   - 12 new tests proving each extension works
+   - WASM size increased by ~100KB (acceptable tradeoff for features)
+
+**Known gaps / unverified claims**
+- No coverage captured
+- `.wishes/wasm-extras.md` satisfied — could move to `.wishes/done/`
+
+---

.tasks/backlog/TASK-065-browser-multitab-integration-polish.md

@@ -0,0 +1,93 @@
+# TASK-065: Browser multi-tab integration polish (F15)
+
+## Status
+- [x] Planned
+- [x] Assigned
+- [x] In Progress
+- [ ] Blocked (reason: ...)
+- [x] Complete
+
+## Priority
+medium
+
+## Assigned To
+subagent (general)
+
+## Parent Docs / Cross-links
+- Unified plan (source of truth): `effect-native/.specs/crsql-mesh/plan.md` Section F (F15)
+- Gap backlog: `research/zig-cr/92-gap-backlog.md`
+
+## Description
+Complete the browser multi-tab integration polish slice from the RGRTDD plan (F15):
+
+- Ensure browser worker modules are tree-shakeable.
+- Ensure the `@effect-native/crsql-mesh` public surface for browser multi-tab is clean and minimal.
+- Verify build output does not accidentally pull in node-only dependencies.
+
+This task is intended as a packaging/build correctness pass, not feature work.
+
+## Files to Modify
+- `effect-native/packages-native/crsql-mesh/src/index.ts`
+- `effect-native/packages-native/crsql-mesh/src/browser/index.ts`
+- `effect-native/packages-native/crsql-mesh/package.json` (if needed)
+- `research/zig-cr/92-gap-backlog.md`
+
+## Acceptance Criteria
+- [x] Browser multi-tab exports are available from `@effect-native/crsql-mesh` without importing node-only code paths.
+- [x] Verification:
+  - `pnpm -F @effect-native/crsql-mesh check` ✓
+  - `pnpm -F @effect-native/crsql-mesh test --run` ✓ (81 tests passed)
+  - `pnpm --filter "@effect-native/crsql-mesh" build` ✓
+
+## Progress Log
+### 2025-12-17
+- Task created during "update tasks" reconciliation from `research/zig-cr/92-gap-backlog.md` remaining F15 work.
+
+## Completion Notes
+
+### 2025-12-16 - Completed (no changes needed)
+
+**Analysis Results:**
+
+The browser multi-tab integration is already correctly structured:
+
+1. **Tree-shakeability verified:**
+   - `src/browser/index.ts` uses explicit named exports (not barrel `export *`)
+   - Each browser module (`coordinator.ts`, `provider.ts`, `coordinator-sw.ts`) is standalone
+   - `coordinator-sw.ts` only uses `import type` from `coordinator.ts` (no runtime dependency)
+
+2. **No node-only dependencies:**
+   - Browser modules have zero external imports - pure TypeScript/browser APIs only
+   - Verified via ripgrep: no imports from `fs`, `path`, `crypto`, `node:`, `child_process`, `os`
+
+3. **Clean public surface:**
+   - Main index: `export * as Browser from "./browser/index.js"` (namespace export)
+   - Direct imports also available: `@effect-native/crsql-mesh/browser/*`
+
+**Verification Commands:**
+
+```
+$ pnpm -F @effect-native/crsql-mesh check
+> tsc -b tsconfig.json
+(no errors)
+
+$ pnpm -F @effect-native/crsql-mesh test --run
+ ✓ test/browser/coordinator-sw.test.ts (12 tests)
+ ✓ test/browser/coordinator.test.ts (18 tests)
+ ✓ test/browser/provider.test.ts (25 tests)
+ ✓ test/IntegrationSqlite.test.ts (3 tests)
+ ✓ test/Receive.test.ts (4 tests)
+ ✓ test/Mesh.test.ts (7 tests)
+ ✓ test/VersionVector.test.ts (3 tests)
+ ✓ test/Integration.test.ts (4 tests)
+ ✓ test/Apply.test.ts (5 tests)
+Test Files  9 passed (9)
+     Tests  81 passed (81)
+
+$ pnpm --filter "@effect-native/crsql-mesh" build
+Successfully compiled 11 files with Babel
+```
+
+**Files Modified:** None - code already meets all acceptance criteria
+
+**Commit:** N/A (no changes)

.tasks/backlog/TASK-067-zig-wasm-baked-in-extensions.md

@@ -0,0 +1,66 @@
+# TASK-067: Zig WASM baked-in extensions (sqlite-vec / FTS / BJSON)
+
+## Status
+- [x] Planned
+- [x] Assigned
+- [x] In Progress
+- [ ] Blocked (reason: ...)
+- [x] Complete
+
+## Priority
+medium
+
+## Assigned To
+subagent (general)
+
+## Parent Docs / Cross-links
+- Wish: `.wishes/wasm-extras.md`
+- Zig wasm build scripts: `zig/wasm-build/`
+- Gap backlog: `research/zig-cr/92-gap-backlog.md` (add a new section under Gaps)
+
+## Description
+Our wasm build does not support loadable extensions. This task bakes a small set of useful extensions into the wasm artifact:
+
+- `sqlite-vec`
+- Full text search (FTS)
+- BJSON
+
+This is strictly about build composition and test evidence; not about exposing a large JS API surface.
+
+## Files to Modify
+- `zig/wasm-build/build-sqlite-wasm.sh`
+- `zig/browser-test/tests/crsql-wasm.spec.ts` (add assertions proving extensions present)
+- `research/zig-cr/92-gap-backlog.md`
+
+## Acceptance Criteria
+- [x] `zig/browser-test/tests/crsql-wasm.spec.ts` contains deterministic evidence that each extension is available.
+- [x] The wasm build includes the extensions without requiring dynamic loading.
+- [x] Verification:
+  - `make -C zig test-browser` (or the repo's existing browser test command)
+
+## Progress Log
+### 2025-12-17
+- Task created from `.wishes/wasm-extras.md` during "update tasks".
+
+### 2025-12-16
+- Modified `zig/wasm-build/build-sqlite-wasm.sh`:
+  - Added Step 2 to download sqlite-vec v0.1.6 amalgamation from GitHub releases
+  - Updated glue code (Step 3) to register sqlite-vec as an auto-extension alongside CR-SQLite
+  - Added compilation of `sqlite-vec.o` with `-DSQLITE_CORE -DSQLITE_VEC_OMIT_FS -DNDEBUG` flags
+  - Added `sqlite-vec.o` to the final linking step
+- Added "Baked-in Extensions" test suite to `zig/browser-test/tests/crsql-wasm.spec.ts`:
+  - FTS5 tests: virtual table creation, full-text search via COUNT(*)
+  - JSON/JSONB tests: `json()`, `json_extract()`, `jsonb()`, `json_array()`, `json_object()`
+  - sqlite-vec tests: `vec_version()`, `vec_f32()`, `vec_distance_l2()`, `vec_distance_cosine()`, `vec0` virtual table, KNN queries
+- Copied updated WASM files to `zig/browser-test/fixtures/` and `zig/browser-dist/`
+- All 30 browser tests pass
+
+## Completion Notes
+### 2025-12-16
+- **Extensions successfully baked into WASM build:**
+  - **FTS5**: Full-text search enabled via `-DSQLITE_ENABLE_FTS5` flag (already in SQLite)
+  - **JSON/JSONB**: JSON1 enabled via `-DSQLITE_ENABLE_JSON1` flag; JSONB built into SQLite 3.45+
+  - **sqlite-vec v0.1.6**: Statically linked, auto-initialized via `sqlite3_auto_extension()`
+- **WASM size**: 1,440,717 bytes (increased from 1,340,272 due to sqlite-vec)
+- **Test verification command**: `make -C zig test-browser` - 30/30 tests pass
+- **Commit**: (pending)