docs(04-01): complete notifications et mode focus plan

- SUMMARY.md with execution results
- STATE.md updated (position, decisions, metrics)
- ROADMAP.md progress updated
- Requirements NOTIF-01, NOTIF-02 marked complete

.planning/phases/04-notifications-et-i3bar/04-01-SUMMARY.md

@@ -0,0 +1,98 @@
+---
+phase: 04-notifications-et-i3bar
+plan: 01
+subsystem: notifications
+tags: [notify-send, dunst, focus-mode, desktop-notifications]
+
+requires:
+  - phase: 03-hooks-claude-code
+    provides: "Hook server, processHookEvent, UpdateFromHook with PrevState tracking"
+provides:
+  - "Notifier interface (ExecNotifier + NullNotifier)"
+  - "FocusTimer thread-safe (Set/IsActive/Remaining)"
+  - "Notification on Working -> Needs Input transition"
+  - "CLI vmux focus <minutes> command"
+affects: [04-02-i3bar]
+
+tech-stack:
+  added: [notify-send via os/exec]
+  patterns: [interface-based notification injection, spy pattern for testing side-effects]
+
+key-files:
+  created: [notify.go, notify_test.go, focus.go, focus_test.go]
+  modified: [daemon.go, hook.go, protocol.go, main.go, daemon_test.go]
+
+key-decisions:
+  - "notify-send via os/exec (pas de lib D-Bus) pour simplicite"
+  - "FocusTimer par timer uniquement, pas de toggle on/off"
+  - "Notification uniquement sur Working -> Needs Input (pas Idle -> Needs Input)"
+
+patterns-established:
+  - "spyNotifier pattern: spy struct pour tester les side-effects de notification"
+  - "Interface injection: Notifier injectable dans Daemon pour testabilite"
+
+requirements-completed: [NOTIF-01, NOTIF-02]
+
+duration: 3min
+completed: 2026-03-23
+---
+
+# Phase 04 Plan 01: Notifications Desktop et Mode Focus Summary
+
+**Notifications dunst via notify-send sur transition Working -> Needs Input, avec mode focus pour supprimer temporairement les alertes**
+
+## Performance
+
+- **Duration:** 3 min
+- **Started:** 2026-03-23T20:23:04Z
+- **Completed:** 2026-03-23T20:26:11Z
+- **Tasks:** 2
+- **Files modified:** 9
+
+## Accomplishments
+- Notifier interface avec ExecNotifier (notify-send --urgency=critical) et NullNotifier
+- FocusTimer thread-safe qui supprime les notifications pendant N minutes
+- Integration dans processHookEvent : notifie uniquement sur Working -> Needs Input
+- CLI `vmux focus <minutes>` pour activer le mode focus
+
+## Task Commits
+
+Each task was committed atomically:
+
+1. **Task 1: Notifier interface, FocusTimer, et tests** - `b96c6d0` (feat)
+2. **Task 2: Integration notifications dans daemon + CLI focus** - `efbe319` (feat)
+
+## Files Created/Modified
+- `notify.go` - Notifier interface, ExecNotifier (notify-send), NullNotifier, shortName helper
+- `notify_test.go` - Tests ExecNotifier, NullNotifier, shortName
+- `focus.go` - FocusTimer struct thread-safe (Set/IsActive/Remaining)
+- `focus_test.go` - Tests FocusTimer Set/Expired/Remaining/ZeroValue
+- `daemon.go` - Champs notifier + focus dans Daemon, handler "focus"
+- `hook.go` - Lecture PrevState avant UpdateFromHook, notification conditionnelle
+- `protocol.go` - FocusArgs, FocusRemaining dans Response
+- `main.go` - CLI "focus <minutes>", usage mis a jour
+- `daemon_test.go` - spyNotifier, tests transitions notification, test focus handler
+
+## Decisions Made
+- notify-send via os/exec avec timeout 5s (pas de lib D-Bus, simplicite)
+- Notification uniquement sur Working -> Needs Input (D-01)
+- Focus = timer uniquement, pas de toggle (D-04)
+- Focus bloque les notifications mais pas l'i3bar (D-05)
+
+## Deviations from Plan
+
+None - plan executed exactly as written.
+
+## Issues Encountered
+None
+
+## User Setup Required
+None - no external service configuration required.
+
+## Next Phase Readiness
+- Notification infrastructure en place, prete pour le widget i3bar (plan 04-02)
+- FocusTimer expose pour usage futur dans l'i3bar
+
+---
+*Phase: 04-notifications-et-i3bar*
+*Completed: 2026-03-23*