docs: Phase 4 + SLICE COMPLETE — REPORT/CONTEXT for v0.56.0

REPORT (Phase 4 FileBrowser scoping + deploy note + monitoring descriptions; live
validation; full slice summary 1/2/2b/3/4 all shipped + validated v0.52->v0.56).
CONTEXT entry.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

CONTEXT.md

@@ -13,6 +13,14 @@ Last updated: 2026-06-12 (storage UX polish)
 > is tracked in `CHANGELOG.md`, `controller/README.md`, and the auto-memory `MEMORY.md`. Live version:
 > **v0.45.0**.
 >
+> **2026-06-13 — v0.56.0 Phase 4: FileBrowser scoping + UI polish (SLICE COMPLETE):**
+> - 4A: FileBrowser bind scoped to `<drive>/appdata` (recovery units + Tier 2 copies under `backups/`
+>   NOT mounted → customer can't browse/delete the restore source). 4B: deploy storage step states
+>   files-on-drive / DB-on-fast-SSD. 4C: `buildStorageBars` stable sort + purpose description on the
+>   monitoring list (user-data drives only; agent local/local-lvm/pbs live on the storage page, not here).
+> - Live-validated (9201): FileBrowser mount `/mnt/felhom-usb/appdata -> /srv/felhom-usb` (backups hidden);
+>   deploy + monitoring text rendered. **All 5 phases (1, 2, 2b, 3, 4) shipped + live-validated, v0.52→v0.56.**
+>
 > **2026-06-13 — v0.55.0 Phase 3: auto off-drive Tier 2 (rootfs-headroom guard):**
 > - `internal/backup/tier2.go`: rsync `-a --delete` of each HDD app's recovery unit + appdata → a
 >   DIFFERENT physical disk (`<target>/backups/secondary/<app>/`). Auto target: prefer another registered