notes(bf-4k9): verify plan.md already up-to-date for dashboard 1.1.0

All required changes were already present in docs/plan/plan.md from
commit cadc7da. This note documents verification of acceptance criteria:
- Header versions match proxy/VERSION and dashboard/VERSION
- Tokens panel row includes cache-read/cache-write series
- Collector fields table includes cache token rates
- Docs inventory lists all four new documents

notes/bf-4k9.md

@@ -0,0 +1,37 @@
+# Bead bf-4k9: Plan.md Already Up-to-Date
+
+## Summary
+
+The task requested updates to `docs/plan/plan.md` to reflect dashboard 1.1.0 cache-token features. Upon investigation, all required changes were already present in the file, having been applied in commit `cadc7da` (docs(plan): update dashboard version to 1.1.0, document cache token features and new docs).
+
+## Verification
+
+All acceptance criteria verified as complete:
+
+1. **Header version**: `Last updated: 2026-07-02, Version: proxy/1.10.0, dashboard/1.1.0` ✓
+   - Matches proxy/VERSION (1.10.0) and dashboard/VERSION (1.1.0)
+
+2. **Tokens panel row** (line 198): `Input + output + cache-read + cache-write token rate (tokens/s) and window running totals` ✓
+   - Documents all four token series tracked by TokenPanel.tsx
+
+3. **Collector snapshot fields** (line 181): `token_rate_cache_read/write | Cache-read/cache-write tokens per second` ✓
+   - Field names verified against dashboard/model/metrics.go:
+     - `TokenRateCacheRead` → `json:"token_rate_cache_read"`
+     - `TokenRateCacheWrite` → `json:"token_rate_cache_write"`
+
+4. **Docs inventory** (lines 407-410): Lists all four new documents ✓
+   - dashboard/README.md
+   - docs/notes/DASHBOARD_API_REFERENCE.md
+   - DEVELOPMENT.md
+   - CONTRIBUTING.md
+
+## Files Verified
+
+- `docs/plan/plan.md` - Already up to date
+- `dashboard/VERSION` - Confirmed as 1.1.0
+- `dashboard/model/metrics.go` - Verified field names match documentation
+- All four doc inventory files confirmed to exist
+
+## Action Taken
+
+No file changes needed; all documentation already accurate. Created this verification note for audit trail.