docs: update project docs for v1.0.0 release

- PROJECT.md: Add peer sync feature description and architecture
- ROADMAP.md: Update to v1.0.0, mark peer sync complete
- TASKS.md: Add peer sync completed tasks, update sprint
- TODO.md: Add multi-scanner section, mark items done
- CHANGELOG.md: Add v0.4.0 (HA) and v1.0.0 (peer sync) entries

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

PROJECT.md

@@ -32,6 +32,10 @@ Understanding the RF environment around you is useful for:
 - **Auto-scan** - Scheduled background scanning
 - **Data Export** - JSON scan history with timestamps
 - **Home Assistant Integration** - Webhook-based presence tracking, new device alerts, departure notifications
+- **Multi-Scanner Peer Sync** - Multiple scanner instances share device metadata automatically
+  - Bidirectional sync with timestamp-based conflict resolution
+  - Source scanner tracking (devices positioned relative to detecting scanner)
+  - Peer scanner markers on 3D map
 
 ## Architecture
 
@@ -74,6 +78,15 @@ Understanding the RF environment around you is useful for:
 │  │   Webhook    │  │   Webhook    │  │   Webhook    │       │
 │  └──────────────┘  └──────────────┘  └──────────────┘       │
 └─────────────────────────────────────────────────────────────┘
+
+┌─────────────────────────────────────────────────────────────┐
+│                    Peer Scanner Sync                         │
+│  ┌──────────────┐            ┌──────────────┐               │
+│  │   Scanner A  │◄── sync ──►│   Scanner B  │               │
+│  │   (rpios)    │            │   (grokbox)  │               │
+│  └──────────────┘            └──────────────┘               │
+│         Shared: floors, labels, favorites, notes            │
+└─────────────────────────────────────────────────────────────┘
 ```
 
 ## Dependencies
@@ -131,9 +144,13 @@ gps:
   longitude: 4.3978
 
 scanner:
+  id: rpios
+  name: "RPi OS Scanner"
   wifi_interface: wlan0
   bt_scan_timeout: 10
   path_loss_exponent: 2.5
+  sync_interval_seconds: 30
+  accept_registrations: true
 
 building:
   enabled: true