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+---
+phase: 03-data-completion
+plan: 08
+subsystem: data-state-events
+tags: [events, anon-tokyo, null-safety, vitest]
+
+# Dependency graph
+requires:
+  - phase: 03-data-completion
+    provides: Eight approved event built-in registrations and their locked parameter contracts
+provides:
+  - Shared runtime parameter guard for all eight registered event built-ins
+  - Real registration-table nullish regression coverage with mutation assertions
+affects: [03-VERIFICATION, Phase 3 data closure]
+
+# Actuals (#2632)
+actuals:
+  tokens: 897
+  tasks: 2
+  commits: 3
+plan_head_before: 4dd28759d8988414a4ec916aa94271fcd370819a
+
+# Tech tracking
+tech-stack:
+  added: []
+  patterns:
+    - Runtime object guard at the AnonTokyo registration adapter before field parsing
+    - Explicit Reflect.apply helper for testing real BuiltInFunction.func values
+
+key-files:
+  created: []
+  modified:
+    - packages-user/data-state/src/event/index.ts
+    - packages-user/data-state/src/event/event.test.ts
+
+key-decisions:
+  - "Guard nullish and non-object parameters only at the shared registration seam, preserving all eight names, signatures, parsers, implementations, and await behavior."
+  - "Exercise null and undefined through the actual createEventBuiltinRegistrations() functions rather than testing implementation helpers directly."
+
+patterns-established:
+  - "Malformed runtime parameters stop before Object.getOwnPropertyDescriptor or event mutation."
+
+requirements-completed: [DATA-01]
+
+coverage:
+  - id: D1
+    description: "All eight approved AnonTokyo event registrations safely resolve void for nullish runtime parameters before parsing."
+    requirement: DATA-01
+    verification:
+      - kind: unit
+        ref: "packages-user/data-state/src/event/event.test.ts#safely resolves nullish parameters through every registered built-in"
+        status: pass
+      - kind: integration
+        ref: "pnpm exec vitest run packages-user/data-state/src/event/event.test.ts packages-user/data-system/src/event/eventDispatch.test.ts"
+        status: pass
+    human_judgment: false
+  - id: D2
+    description: "Existing valid event behavior, registration order, async waiting, and missing-target safe failures remain covered and green."
+    requirement: DATA-01
+    verification:
+      - kind: unit
+        ref: "packages-user/data-state/src/event/event.test.ts#event built-ins"
+        status: pass
+      - kind: other
+        ref: "pnpm test:ci packages-user/data-common packages-user/data-base packages-user/data-system packages-user/data-state"
+        status: pass
+    human_judgment: false
+
+# Metrics
+duration: 6 min
+completed: 2026-09-10
+status: complete
+commits: 3
+---
+
+# Phase 3 Plan 8 Summary
+
+**Null-safe runtime guards and real registration-table regression coverage for all eight approved event built-ins**
+
+## Performance
+
+- **Duration:** 6 min
+- **Started:** 2026-09-10T18:45:00+08:00
+- **Completed:** 2026-09-10T18:51:15+08:00
+- **Tasks:** 2
+- **Files modified:** 2
+
+## Accomplishments
+
+- Added a shared `createBuiltin` boundary guard that returns resolved `void` for nullish or otherwise non-object runtime parameters before parser property access
+- Added a focused real-registration `eventSetBlock(null)` regression and a matrix covering null and undefined for all eight approved registrations
+- Preserved the locked built-in names, parameter contracts, valid parsing, awaited event behavior, registration order, and state mutation semantics
+
+## Task Commits
+
+Each task was committed atomically:
+
+1. **Task 1: GAP-03-02 guard the registered event built-in entry seam** - `95df6a0` (fix)
+2. **Task 2: GAP-03-02 nullish regression matrix for all eight registrations** - `f8cae08` (test)
+
+Additional quality commit:
+
+3. **Prettier/CRLF normalization for changed event files** - `82687b2` (style)
+
+**Plan metadata:** pending final metadata commit
+
+## Files Created/Modified
+
+- `packages-user/data-state/src/event/index.ts` - shared runtime parameter guard at the registration adapter
+- `packages-user/data-state/src/event/event.test.ts` - actual registration seam null/undefined matrix and unchanged-state assertions
+
+## Decisions Made
+
+- Kept the correction at the registration boundary so the approved public contracts and underlying implementations remain unchanged
+- Used an explicit runtime invocation helper based on `Reflect.apply` to pass nullish values through real `BuiltInFunction.func` values without weakening public interfaces or adding an `any` escape
+
+## Deviations from Plan
+
+### Auto-fixed Issues
+
+**1. [Rule 3 - Blocking] Applied required CRLF and Prettier formatting**
+
+- **Found during:** Overall quality-gate checks after Task 2
+- **Issue:** The first patch left the two changed files in a formatting state rejected by the repository ESLint/Prettier checks
+- **Fix:** Ran Prettier write on only the two plan-owned files and committed the resulting line-ending/layout normalization
+- **Files modified:** `packages-user/data-state/src/event/index.ts`, `packages-user/data-state/src/event/event.test.ts`
+- **Verification:** Focused ESLint, Prettier check, and focused event tests passed
+- **Committed in:** `82687b2`
+
+---
+
+**Total deviations:** 1 auto-fixed (Rule 3: 1)
+**Impact on plan:** Required formatting correction only; no scope or runtime contract expansion.
+
+## Verification
+
+- `pnpm exec vitest run packages-user/data-state/src/event/event.test.ts` — passed, 10 tests
+- `pnpm exec vitest run packages-user/data-state/src/event/event.test.ts packages-user/data-system/src/event/eventDispatch.test.ts` — passed, 16 tests
+- `pnpm test:ci packages-user/data-common packages-user/data-base packages-user/data-system packages-user/data-state` — passed, 18 files / 100 tests
+- `pnpm exec tsx script/check-data-type.ts` — passed with 0 in-scope data-package diagnostics; 27 pre-existing outside-scope diagnostics reported
+- `pnpm exec tsx script/check-data-circular.ts` — passed with 0 cycles
+- `pnpm exec eslint packages-user/data-state/src/event/index.ts packages-user/data-state/src/event/event.test.ts` — passed
+- `pnpm exec prettier --check packages-user/data-state/src/event/index.ts packages-user/data-state/src/event/event.test.ts` — passed
+
+## Issues Encountered
+
+- The type gate continues to report the repository's known 27 diagnostics outside the four data-package scope; the scoped gate passed and no changed event file was implicated.
+- Existing tests emit expected warnings for intentionally missing event ids and unknown fixture tiles; all assertions passed.
+
+## User Setup Required
+
+None - no external service configuration required.
+
+## Next Phase Readiness
+
+- GAP-03-02 is closed: all eight real registered built-ins resolve safely for both `null` and `undefined` without state mutation.
+- Locked event contracts and valid awaited behavior remain intact.
+- `.planning/STATE.md` and `.planning/ROADMAP.md` were intentionally not modified per the execution request.
+
+---
+*Phase: 03-data-completion*
+*Completed: 2026-09-10*
+
+## Self-Check: PASSED
+
+- Summary file exists
+- Task commits `95df6a0`, `f8cae08`, and formatting commit `82687b2` are present in git history
+- Focused tests, four-package data suite, type gate, circular gate, ESLint, and Prettier checks passed