feat: #78 Excalidraw finitions + #67 push + #68 health-detailed + #77 desktop jumplist

#78 Excalidraw — finitions B5/C8/F2/F3
- backend/indexer.py: port Python pur de lz-string decompressFromBase64 (bitsPerChar=6, resetValue=32) validé contre 4 fixtures JS truth (texte accentué, edge cases) — remplace le stub base64 non-fonctionnel
- B5 indexation: .excalidraw.md (format plugin Obsidian) maintenant décompressé côté Python → texte indexé pour recherche TF-IDF
- 7 nouveaux tests B5 dans tests/test_excalidraw.py (13/13 total)
- F2: excalidraw-viewer.test.mjs enregistré dans CI (lint job)
- F3: tests/e2e/excalidraw.spec.js (9 specs — ouverture .excalidraw/.excalidraw.md, création via modale/menu contextuel, toolbar, thème, pop-out, recherche)
- Fixtures test_vault/diagram.excalidraw + diagram.excalidraw.md

#67 Push notifications (Web Push API + VAPID)
- backend/push.py: router + VAPID keys + send_push_notification (pywebpush>=2.3.0)
- frontend/js/push.js: subscription UI + service worker integration
- tests/test_push.py: 10 tests (subscribe/list/unsubscribe/vapid key)
- requirements.txt + sw.js + locales push strings

#68 Health check enrichi
- backend/main.py: GET /api/health/detailed (admin) — memory/cpu/disk/backups/index/SSE connections
- backend/indexer.py: _last_full_index_ts tracking
- tests/conftest.py: admin_client fixture
- tests/test_api_main.py: 3 nouveaux tests health detailed

#77 Desktop jumplist
- desktop/src/jumplist.rs: Windows jumplist integration
- Cargo.toml/lock + capabilities + main.rs
- frontend/js/desktop.js: Tauri bridge (isTauriEnv, invoke, getSystemTheme, syncSystemTheme, shouldShowWizard, crash banner)
- tests/frontend/desktop.test.mjs: 21 tests JSDOM (détection, invoke degradation, theme gating, wizard, crash banner)
- tests/frontend/unit.test.mjs: desktop.js whitelisted (standalone global reader)

# Frontend & CI
- frontend/sw.js: réécriture complète (precache + push event handlers + offline)
- frontend/index.html: section push dans settings + about repositionné
- frontend/js/app.js: initDesktopIntegration + initPush
- CI .gitea/workflows/ci.yml: excalidraw-viewer.test.mjs ajouté au lint job

All checks: ruff clean, 552 backend tests pass, 9 frontend unit, 5 excalidraw-viewer, 21 desktop, 9 pane-manager, validate-imports 33 modules.

backend/main.py

@@ -290,6 +290,9 @@ class HealthResponse(BaseModel):
     version: str = Field(description="Application version (x.y.z — latest release tag)")
     vaults: int = Field(description="Number of configured vaults")
     total_files: int = Field(description="Total indexed files across all vaults")
+    total_tokens: int = Field(description="Total indexed tokens (approx.) across all vaults", default=0)
+    last_full_index_ts: str = Field(description="ISO timestamp of last full index rebuild", default="")
+    uptime_seconds: int = Field(description="Server uptime in seconds", default=0)
     git_describe: str = Field(default="", description="Full git describe string (commits beyond tag), empty if no git")
     git_commit: str = Field(default="", description="Short HEAD commit hash, empty if no git")
 
@@ -727,6 +730,14 @@ try:
 except ImportError as e:
     logger.warning(f"Could not load admin dashboard router: {e}")
 
+# Push Notifications endpoints (Web Push API + VAPID)
+try:
+    from backend.push import router as push_router
+    app.include_router(push_router)
+    logger.info("Push notifications router mounted at /api/push/*")
+except ImportError as e:
+    logger.warning(f"Could not load push notifications router: {e}")
+
 # Resolve frontend path relative to this file
 FRONTEND_DIR = Path(__file__).resolve().parent.parent / "frontend"
 
@@ -1042,16 +1053,115 @@ async def api_health():
         Application status, version, vault count and total file count.
     """
     total_files = sum(len(v["files"]) for v in index.values())
+    total_tokens = sum(len(v.get("files", [])) * 1000 for v in index.values())  # rough approx
+    import time
+
+    from backend.indexer import _last_full_index_ts
+    uptime = int(time.time() - _SERVER_START_TIME) if '_SERVER_START_TIME' in globals() else 0
     return {
         "status": "ok",
         "version": app.version,
         "vaults": len(index),
         "total_files": total_files,
+        "total_tokens": total_tokens,
+        "last_full_index_ts": _last_full_index_ts,
+        "uptime_seconds": uptime,
         "git_describe": get_git_describe(),
         "git_commit": get_git_commit(),
     }
 
 
+@app.get("/api/health/detailed", response_model=HealthResponse)
+async def api_health_detailed(current_user=Depends(require_admin)):
+    """Detailed health check — admin only.
+
+    Returns enriched metrics including memory, disk, SSE connections, and backup stats.
+    """
+
+    import psutil
+
+    from backend.admin import _count_active_sessions, _get_disk_stats
+    from backend.indexer import _last_full_index_ts, index
+    
+    total_files = sum(len(v["files"]) for v in index.values())
+    total_tokens = sum(len(v.get("files", [])) * 1000 for v in index.values())
+    import time
+    uptime = int(time.time() - _SERVER_START_TIME) if '_SERVER_START_TIME' in globals() else 0
+    
+    # Memory
+    vm = psutil.virtual_memory()
+    mem_used_mb = round(vm.used / (1024 ** 2), 1)
+    mem_total_mb = round(vm.total / (1024 ** 2), 1)
+    mem_pct = round(vm.percent, 1)
+    
+    # CPU
+    cpu_pct = psutil.cpu_percent(interval=None)
+    
+    # Disk
+    disk_used_gb, disk_total_gb = _get_disk_stats()
+    disk_free_gb = round(disk_total_gb - disk_used_gb, 2)
+    disk_pct = round((disk_used_gb / disk_total_gb * 100) if disk_total_gb > 0 else 0, 1)
+    
+    # SSE connections (approximation)
+    active_sessions = _count_active_sessions()
+    
+    # Backups
+    from backend.admin import _scan_backups
+    backup_rows = _scan_backups()
+    total_backups = len(backup_rows)
+    total_backup_size_mb = round(sum(r["size"] for r in backup_rows) / (1024 ** 2), 2)
+    oldest_backup_age_days = 0.0
+    if backup_rows:
+        now_ts = int(time.time())
+        oldest_ts = min(r["timestamp"] for r in backup_rows)
+        oldest_backup_age_days = round((now_ts - oldest_ts) / 86400, 2)
+    
+    # Index details
+    index_detail = {}
+    for name, data in index.items():
+        index_detail[name] = {
+            "file_count": len(data["files"]),
+            "tag_count": len(data["tags"]),
+            "token_count_approx": len(data.get("files", [])) * 1000,
+        }
+    
+    return {
+        "status": "ok",
+        "version": app.version,
+        "vaults": len(index),
+        "total_files": total_files,
+        "total_tokens": total_tokens,
+        "last_full_index_ts": _last_full_index_ts,
+        "uptime_seconds": uptime,
+        "git_describe": get_git_describe(),
+        "git_commit": get_git_commit(),
+        # Enriched fields
+        "memory": {
+            "used_mb": mem_used_mb,
+            "total_mb": mem_total_mb,
+            "percent": mem_pct,
+        },
+        "cpu": {
+            "percent": cpu_pct,
+        },
+        "disk": {
+            "used_gb": disk_used_gb,
+            "total_gb": disk_total_gb,
+            "free_gb": disk_free_gb,
+            "percent": disk_pct,
+        },
+        "connections": {
+            "active_sse": active_sessions,
+        },
+        "backups": {
+            "total_count": total_backups,
+            "total_size_mb": total_backup_size_mb,
+            "oldest_age_days": oldest_backup_age_days,
+        },
+        "index": index_detail,
+    }
+
+
 @app.get("/api/vaults", response_model=list[VaultInfo])
 async def api_vaults(current_user=Depends(require_auth)):
     """List configured vaults the user has access to.