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+---
+phase: 08-backend-aggregation-filtering
+plan: 01
+subsystem: backend-service
+tags: [php, aggregation, filtering, timezone, tdd]
+dependency_graph:
+  requires: []
+  provides: [getHourlyAggregation, getDayHourAggregation, getUserCustomers, getUserActivities, filter-params]
+  affects: [Controller/HeatmapController.php, DependencyInjection]
+tech_stack:
+  added: []
+  patterns: [native-sql-dbal, timezone-offset-convert_tz, weekstart-day-remapping, entity-manager-injection]
+key_files:
+  created: []
+  modified:
+    - Service/HeatmapService.php
+    - Tests/Service/HeatmapServiceTest.php
+    - Tests/bootstrap.php
+decisions:
+  - Inject EntityManagerInterface as second constructor param instead of accessing via protected getEntityManager() on TimesheetRepository -- enables clean mocking
+  - Use subquery for customer filter in native SQL instead of JOIN to keep SQL builder logic simple
+metrics:
+  duration_seconds: 466
+  completed: "2026-04-09T19:25:45Z"
+  tasks_completed: 1
+  tasks_total: 1
+  test_count: 13
+  test_pass: 13
+---
+
+# Phase 8 Plan 01: Backend Aggregation + Filter Methods Summary
+
+Extended HeatmapService with hourly/day-hour aggregation via native SQL CONVERT_TZ, cascade entity queries (customers/activities), and activity/customer filter params on all aggregation methods.
+
+## Tasks Completed
+
+| # | Task | Commit | Key Changes |
+|---|------|--------|-------------|
+| 1 | Add aggregation methods and filter support (TDD) | 8a0e5de (RED), c28220c (GREEN) | 4 new service methods, 10 new tests, filter params on getDailyAggregation |
+
+## Implementation Details
+
+### New Service Methods
+
+- **getHourlyAggregation**: Native SQL with `CONVERT_TZ(start_time, '+00:00', :tz)` for timezone-correct hour grouping. Returns `{hour, hours, count}`.
+- **getDayHourAggregation**: Native SQL with `DAYOFWEEK(date_tz)` remapped to 0-6 relative to weekStart preference. Returns `{day, hour, hours, count}`.
+- **getUserCustomers**: DQL via QueryBuilder joining through project to customer. Returns `{id, name}`.
+- **getUserActivities**: DQL via QueryBuilder with optional projectId scope. Returns `{id, name}`.
+
+### Extended Methods
+
+- **getDailyAggregation**: Added `?int $customerId` and `?int $activityId` params with parameterized WHERE clauses.
+
+### Architecture Change
+
+Injected `EntityManagerInterface` as second constructor parameter to HeatmapService. This replaces the previous pattern of calling the protected `getEntityManager()` on TimesheetRepository, which cannot be mocked in PHPUnit. Symfony autowiring handles the injection automatically.
+
+### Test Infrastructure
+
+Added `createServiceWithNativeResults()` helper for mocking DBAL Connection chain (Result -> Connection -> EntityManager). Updated `createServiceWithResults()` to stub `join()` and pass EntityManager mock.
+
+Updated `Tests/bootstrap.php` with a prepended autoloader for worktree contexts.
+
+## Deviations from Plan
+
+### Auto-fixed Issues
+
+**1. [Rule 3 - Blocking] EntityManager access pattern incompatible with PHPUnit mocking**
+- **Found during:** Task 1 (RED phase)
+- **Issue:** `TimesheetRepository::getEntityManager()` is protected in Doctrine's EntityRepository, making it impossible to mock via `createMock()`. Using `getMockBuilder()->onlyMethods()` also failed because the mock's `__call` magic intercepted the call.
+- **Fix:** Added `EntityManagerInterface` as second constructor parameter to HeatmapService. Symfony autowiring handles injection; tests pass a mock directly.
+- **Files modified:** Service/HeatmapService.php, Tests/Service/HeatmapServiceTest.php
+- **Commit:** c28220c
+
+**2. [Rule 3 - Blocking] Worktree autoloader resolving classes from main repo**
+- **Found during:** Task 1 (GREEN phase)
+- **Issue:** Composer's classmap in Kimai's vendor directory resolves plugin classes via the symlink to the main repo, ignoring worktree file changes.
+- **Fix:** Added prepended `spl_autoload_register` in Tests/bootstrap.php that resolves `KimaiPlugin\KimaiHeatmapBundle\` from the current directory before Composer's classmap.
+- **Files modified:** Tests/bootstrap.php
+- **Commit:** c28220c
+
+## Verification
+
+- PHPUnit: 13 tests, 40 assertions, 0 failures
+- All 6 public business methods present on HeatmapService
+- All native SQL uses parameterized queries (no string interpolation)
+- All queries include user scope constraint
+
+## Self-Check: PASSED