docs(02-02): complete DELETE logs endpoint plan — summary and state update

- 02-02-SUMMARY.md: backend DELETE endpoint + frontend deleteLog wiring
- STATE.md: phase 2 marked complete, decisions added, position advanced to phase 3 ready

.planning/STATE.md

@@ -5,33 +5,33 @@
 See: .planning/PROJECT.md (updated 2026-02-15)
 
 **Core value:** Logging a workout should be fast, clear, and flexible — the app never fights the user during a session
-**Current focus:** Phase 1 — Input UX
+**Current focus:** Phase 2 — Flexible Sets (complete)
 
 ## Current Position
 
-Phase: 2 of 3 (Flexible Sets)
+Phase: 2 of 3 (Flexible Sets) — COMPLETE
-Plan: 1 of 2 in current phase (02-01 complete)
+Plan: 2 of 2 in current phase (02-01 and 02-02 complete)
-Status: Phase 2 in progress — plan 02-01 done, 02-02 pending
+Status: Phase 2 complete — ready for Phase 3 planning
-Last activity: 2026-02-21 — Completed 02-01 (ExerciseCard dynamic setList, add-set modal, delete-set)
+Last activity: 2026-02-21 — Completed 02-02 (DELETE /api/logs endpoint + deleteLog wiring)
 
-Progress: [█████░░░░░] 50%
+Progress: [███████░░░] 67%
 
 ## Performance Metrics
 
 **Velocity:**
-- Total plans completed: 3
+- Total plans completed: 5
-- Average duration: ~1.3 min
+- Average duration: ~2.8 min
-- Total execution time: ~0.07 hours
+- Total execution time: ~0.23 hours
 
 **By Phase:**
 
 | Phase | Plans | Total | Avg/Plan |
 |-------|-------|-------|----------|
 | 01-input-ux | 3/3 | ~4 min | ~1.3 min |
-| 02-flexible-sets | 1/2 | ~8 min | ~8 min |
+| 02-flexible-sets | 2/2 | ~10 min | ~5 min |
 
 **Recent Trend:**
-- Last 5 plans: 01-01 (1 min), 01-03 (2 min), 01-02 (1 min), 02-01 (8 min)
+- Last 5 plans: 01-01 (1 min), 01-03 (2 min), 01-02 (1 min), 02-01 (8 min), 02-02 (2 min)
 - Trend: fast
 
 *Updated after each plan completion*
@@ -54,7 +54,9 @@ Progress: [█████░░░░░] 50%
 - Dropset weight drops: 80% then 60% of base weight, each rounded to nearest 2.5kg per app progression convention
 - Last-set guard: handleDeleteSet returns early if setList.length <= 1, delete button also disabled in DOM
 - progress-badge and all-done class reference setList.length instead of exercise.sets — badge reflects actual set count
-- onDeleteSet prop is optional stub in ExerciseCard — backend wiring deferred to plan 02-02
+- No authMiddleware on DELETE /api/logs — consistent with POST /api/logs which also passes user_id in body
+- deleteLog silently ignores 404 from backend — unlogged sets deleted mid-session cause no harm
+- Composite key (user_id, program_exercise_id, date, set_number) uniquely identifies a workout set log row for deletion
 
 ### Pending Todos
 
@@ -67,5 +69,5 @@ None yet.
 ## Session Continuity
 
 Last session: 2026-02-21
-Stopped at: Completed 02-01-PLAN.md (ExerciseCard dynamic setList, add-set modal, delete-set button)
+Stopped at: Completed 02-02-PLAN.md (DELETE /api/logs endpoint + deleteLog wiring through App.jsx and WorkoutPage)
 Resume file: None

.planning/phases/02-flexible-sets/02-02-SUMMARY.md

@@ -0,0 +1,116 @@
+---
+phase: 02-flexible-sets
+plan: "02"
+subsystem: api
+tags: [express, postgres, react, fetch, delete, workout-logs]
+
+# Dependency graph
+requires:
+  - phase: 02-flexible-sets
+    plan: "01"
+    provides: ExerciseCard with handleDeleteSet calling optional onDeleteSet prop (stub — wired here)
+provides:
+  - DELETE /api/logs endpoint in backend/src/index.js
+  - deleteLog function in App.jsx calling DELETE /api/logs
+  - onDeleteSet prop wired from App.jsx -> WorkoutPage -> ExerciseCard
+affects: [03-custom-workouts, backend-logging]
+
+# Tech tracking
+tech-stack:
+  added: []
+  patterns: [DELETE endpoint with composite key (user_id, program_exercise_id, date, set_number), optimistic local state removal mirrors DB delete]
+
+key-files:
+  created: []
+  modified:
+    - backend/src/index.js
+    - frontend/src/App.jsx
+    - frontend/src/pages/WorkoutPage.jsx
+
+key-decisions:
+  - "No authMiddleware on DELETE /api/logs — consistent with existing POST /api/logs which also passes user_id in body"
+  - "deleteLog silently ignores 404 responses — backend handles non-existent row gracefully (unlogged sets deleted mid-session)"
+  - "Local logs state updated optimistically after DELETE regardless of 404 — ensures UI stays consistent even for never-logged sets"
+
+patterns-established:
+  - "Composite-key delete: (user_id, program_exercise_id, date, set_number) is the unique identifier for a workout set log row"
+  - "Prop threading: deleteLog lives in App.jsx, flows as onDeleteSet -> WorkoutPage -> ExerciseCard without intermediate handlers"
+
+# Metrics
+duration: 2min
+completed: 2026-02-21
+---
+
+# Phase 2 Plan 02: Flexible Sets — Backend DELETE Endpoint and Frontend Wiring Summary
+
+**DELETE /api/logs endpoint deletes workout_logs rows by composite key; deleteLog in App.jsx propagates through WorkoutPage to ExerciseCard, removing orphaned set rows from DB when user deletes a set**
+
+## Performance
+
+- **Duration:** ~2 min
+- **Started:** 2026-02-21T17:44:02Z
+- **Completed:** 2026-02-21T17:45:45Z
+- **Tasks:** 2
+- **Files modified:** 3
+
+## Accomplishments
+
+- Backend DELETE /api/logs endpoint: deletes matching workout_logs row by composite key (user_id, program_exercise_id, date, set_number), returns 200+id on success, 404 if not found
+- deleteLog async function added to App.jsx alongside logSet: sends DELETE fetch, removes entry from local logs state on success
+- Full prop chain wired: App.jsx onDeleteSet={deleteLog} -> WorkoutPage signature updated to accept onDeleteSet -> ExerciseCard receives onDeleteSet prop (was already calling it if provided from plan 01)
+- Frontend build passes cleanly after changes
+
+## Task Commits
+
+Each task was committed atomically:
+
+1. **Task 1: Add DELETE /api/logs endpoint to backend** - `f9eb6cc` (feat)
+2. **Task 2: Wire deleteLog through App.jsx and WorkoutPage to ExerciseCard** - `175434f` (feat)
+
+**Plan metadata:** committed with docs commit (docs)
+
+## Files Created/Modified
+
+- `backend/src/index.js` - Added DELETE /api/logs route (21 lines) after POST /api/logs, same composite key pattern
+- `frontend/src/App.jsx` - Added deleteLog function (20 lines), added onDeleteSet={deleteLog} prop to WorkoutPage render
+- `frontend/src/pages/WorkoutPage.jsx` - Updated function signature to accept onDeleteSet, passed onDeleteSet to each ExerciseCard
+
+## Decisions Made
+
+- **No auth on DELETE /api/logs:** POST /api/logs has no authMiddleware — DELETE matches that pattern for consistency; user_id from body provides identity
+- **Silent 404 handling:** If a set was never logged (user added then immediately deleted without completing), the DELETE returns 404. deleteLog catches silently — the row never existed, no cleanup needed
+- **Optimistic state update:** Local logs state is always updated (filter out the set_number) regardless of whether the DELETE returned 200 or 404, since in both cases the set should not appear in the UI
+
+## Deviations from Plan
+
+None — plan executed exactly as written.
+
+## Issues Encountered
+
+None — build passed cleanly after both tasks. Backend syntax verified with `node --check`.
+
+## User Setup Required
+
+None - no external service configuration required.
+
+## Next Phase Readiness
+
+- Phase 2 (Flexible Sets) is now complete: ExerciseCard supports dynamic set lists (plan 01), and deleting a logged set removes it from the database (plan 02)
+- Ghost sets can no longer reappear after page reload — deleted sets are removed from both frontend state and backend DB
+- Phase 3 (Custom Workouts) requires new DB tables (custom_workouts, custom_workout_exercises) and a source_type column on workout_logs — schema migration needed before Phase 3 planning
+
+## Self-Check: PASSED
+
+- backend/src/index.js: FOUND
+- frontend/src/App.jsx: FOUND
+- frontend/src/pages/WorkoutPage.jsx: FOUND
+- 02-02-SUMMARY.md: FOUND
+- Commit f9eb6cc (Task 1): FOUND
+- Commit 175434f (Task 2): FOUND
+- DELETE /api/logs in backend: FOUND
+- deleteLog in App.jsx: FOUND
+- onDeleteSet prop wired through WorkoutPage: FOUND
+
+---
+*Phase: 02-flexible-sets*
+*Completed: 2026-02-21*