diff --git a/.planning/STATE.md b/.planning/STATE.md
index a790186..052eca3 100644
--- a/.planning/STATE.md
+++ b/.planning/STATE.md
@@ -3,8 +3,8 @@ gsd_state_version: 1.0
 milestone: v1.0
 milestone_name: milestone
 status: executing
-stopped_at: Completed 03-01-PLAN.md
-last_updated: "2026-04-08T11:12:34.889Z"
+stopped_at: Completed 03-03-PLAN.md
+last_updated: "2026-04-08T11:21:00Z"
 last_activity: 2026-04-08
 progress:
   total_phases: 5
@@ -54,6 +54,7 @@ Progress: [██░░░░░░░░] 20%
 *Updated after each plan completion*
 | Phase 2 P02-01 | 5min | 5 tasks | 8 files |
 | Phase 03 P01 | 3min | 4 tasks | 7 files |
+| Phase 03 P03 | 2min | 4 tasks | 1 files |
 
 ## Accumulated Context
 
@@ -74,6 +75,7 @@ Recent decisions affecting current work:
 - [Phase 1]: process-compose API server disabled (-p 0) to avoid port 8080 conflict
 - [Phase 2]: Removed final from HeatmapService to allow PHPUnit mocking
 - [Phase 03]: IIFE format with KimaiHeatmap global for browser compat
+- [Phase 03]: kimai.initialized event for deferred widget init, javascriptRequest fallback for AJAX
 
 ### Pending Todos
 
@@ -85,6 +87,6 @@ None yet.
 
 ## Session Continuity
 
-Last session: 2026-04-08T11:12:34.887Z
-Stopped at: Completed 03-01-PLAN.md
+Last session: 2026-04-08T11:21:00Z
+Stopped at: Completed 03-03-PLAN.md
 Resume file: None
diff --git a/.planning/phase-3/03-03-SUMMARY.md b/.planning/phase-3/03-03-SUMMARY.md
new file mode 100644
index 0000000..7057d4f
--- /dev/null
+++ b/.planning/phase-3/03-03-SUMMARY.md
@@ -0,0 +1,76 @@
+---
+phase: "03"
+plan: "03"
+subsystem: ui
+tags: [twig, kimai-widget, asset-serving, d3]
+dependency_graph:
+  requires:
+    - phase: "03-01"
+      provides: js-build-pipeline
+    - phase: "03-02"
+      provides: d3-heatmap-code
+  provides: [dashboard-widget-rendering, asset-symlinks]
+  affects: [Resources/views/]
+tech_stack:
+  added: []
+  patterns: [kimai-initialized-event, iife-init-pattern, asset-bundle-symlink]
+key_files:
+  created: []
+  modified:
+    - Resources/views/widget/heatmap.html.twig
+decisions:
+  - "Use kimai.initialized event for deferred init, with javascriptRequest fallback for AJAX loads"
+metrics:
+  duration: "2min"
+  completed: "2026-04-08"
+---
+
+# Phase 3 Plan 03: Twig Template + Asset Serving Summary
+
+**Wired d3 heatmap JS/CSS into Kimai dashboard widget via asset() helper and kimai.initialized event listener**
+
+## Performance
+
+- **Duration:** 2 min
+- **Started:** 2026-04-08T11:19:31Z
+- **Completed:** 2026-04-08T11:21:00Z
+- **Tasks:** 4
+- **Files modified:** 1
+
+## Accomplishments
+
+- Updated widget template to load heatmap.css and heatmap.js via Symfony asset() helper
+- Added KimaiHeatmap.init() call with proper Kimai lifecycle event handling
+- Installed assets as symlinks into dev Kimai instance
+- Verified all tests pass (20 JS tests, 4 PHP tests) and build succeeds
+
+## Commits
+
+| Task | Commit | Description |
+|------|--------|-------------|
+| 1-4  | ac198ff | feat: wire heatmap JS/CSS into dashboard widget template |
+
+## Files Created/Modified
+
+- `Resources/views/widget/heatmap.html.twig` -- Replaced placeholder with asset loading, d3 heatmap init, and Kimai event wiring
+
+## Decisions Made
+
+- Use `kimai.initialized` DOM event for deferred widget init, with `kimai_context.javascriptRequest` check for AJAX-loaded dashboard panels
+
+## Deviations from Plan
+
+None -- plan executed exactly as written.
+
+## Issues Encountered
+
+None
+
+## Next Phase Readiness
+
+- Heatmap widget fully wired: template loads CSS/JS and initializes d3 visualization
+- Ready for Phase 4 (integration testing with running Kimai instance)
+
+---
+*Phase: 03*
+*Completed: 2026-04-08*