docs(bf-53q6): note that feature was already complete

The system cgroup memory panel for the web dashboard was already fully implemented:
- Backend: systemCgroupMonitor.ts with memory sampling
- API: /api/system/memory, /api/system/memory/history, /api/alerts/oom
- Frontend: SystemMemoryIndicator (header) + SystemMemoryPanel (detail)
- Integration: App.tsx lines 24, 28, 270, 872-878, 928, 1122-1127

All 2511 tests pass. No additional work required.

notes/bf-53q6.md

@@ -1,53 +1,53 @@
-# bf-53q6: System Cgroup Memory Panel - Already Complete
+# Task bf-53q6: System cgroup memory panel for web dashboard
 
-## Task
-Add system cgroup memory panel to web dashboard (real-time utilization + OOM event counter)
+## Status: Feature Already Complete
 
-## Status
-**ALREADY COMPLETE** - This bead was implemented in prior commits.
+This task requested adding a system cgroup memory panel to the FABRIC web dashboard with:
+- Current cgroup memory usage vs MemoryHigh (progress bar with color coding)
+- 5-minute sparkline of memory.current sampled every 10s
+- oom_kill counter from memory.events
+- Swap usage if enabled
 
-## Implementation Details
+## Implementation Summary
 
-### Backend (src/systemCgroupMonitor.ts + src/web/server.ts)
-- `systemCgroupMonitor.ts` reads cgroup memory stats from `/sys/fs/cgroup/user.slice/user-1001.slice/`
-  - memory.current (usage)
-  - memory.high (soft limit)
-  - memory.max (hard limit)
-  - memory.events (oom_kill counter)
-  - memory.swap.current (swap usage)
-- Background sampler runs every 10s, maintaining 30-sample history (5 minutes)
-- API endpoints:
-  - `GET /api/system/memory` - current status
-  - `GET /api/system/memory/history` - sparkline data
-  - `GET /api/system/memory/summary` - formatted summary
+The feature was already fully implemented in the codebase:
+
+### Backend (src/systemCgroupMonitor.ts)
+- `getSystemMemoryStatus()` - Reads cgroup memory stats from /sys/fs/cgroup/user.slice/user-1001.slice/
+- `getMemoryHistory()` - Returns 5-minute history (30 samples @ 10s intervals)
+- `startMemorySampler()` - Background sampler (started in server.ts at line 1745)
+- OOM kill parsing from memory.events
+- Swap usage reading from memory.swap.current
+
+### API Endpoints (src/web/server.ts)
+- `GET /api/system/memory` - Returns current memory status with formatted values
+- `GET /api/system/memory/history` - Returns memory history for sparkline
+- `GET /api/alerts/oom` - Returns OOM risk alert
 
 ### Frontend Components
-- `SystemMemoryIndicator.tsx` (7.5KB)
-  - Compact progress bar (green <70%, yellow 70-90%, red >90%)
-  - 5-minute sparkline (30 bars, sampled every 10s)
-  - OOM kill counter badge
-  - Swap indicator
-  - Updates every 10s via polling
+1. **SystemMemoryIndicator.tsx** (compact indicator in fleet header)
+   - Progress bar (green <70%, yellow 70-90%, red >90%)
+   - 5-minute sparkline (30 samples)
+   - OOM kill counter (💀 icon)
+   - Swap indicator (🔁 icon)
 
-- `SystemMemoryPanel.tsx` (23KB)
-  - Full detail modal with all cgroup stats
-  - System memory section (total, available)
-  - Swap section (total, free, used bar)
-  - FABRIC process RSS
-  - OOM risk legend
-  - Refresh button
+2. **SystemMemoryPanel.tsx** (full detail panel)
+   - All above features plus:
+   - Detailed memory sections (Cgroup, System, Swap, FABRIC Process)
+   - OOM risk legend
+   - Auto-refresh every 5 seconds
 
-### Integration (App.tsx)
-- SystemMemoryIndicator in fleet header (line 928)
-- SystemMemoryPanel as modal (lines 1122-1125)
-- Toggle button in header (lines 872-877)
-
-## Related Commits
-- `81b57e6` refactor(bf-53q6): add SystemMemoryIndicator to fleet header and clean up cgroup monitor
-- `83baf06` feat(bf-53q6): integrate SystemMemoryPanel into FABRIC web dashboard
-- `820e509` feat(bf-53q6): integrate SystemMemoryPanel into FABRIC web dashboard
+### Integration (src/web/frontend/src/App.tsx)
+- Line 24: Import SystemMemoryIndicator
+- Line 28: Import SystemMemoryPanel
+- Line 928: Indicator in fleet header
+- Lines 1122-1127: Full panel with visibility toggle
+- Lines 872-878: Toggle button in header
 
 ## Verification
-- ✅ Web build successful (`npm run build:web`)
-- ✅ Type check passes (`tsc --noEmit`, excluding unrelated OTLP test errors)
-- ✅ All files committed and pushed
+
+- All 2511 tests pass
+- Memory sampler runs at 10s intervals (configured in server.ts)
+- UI components properly integrated in the dashboard
+
+No additional work required.