v0.12.0 — Backup page overhaul: unified app rows, bug fixes, sequential chaining

Bug fixes:
- GetFullStatus() returns deep copy; CrossDriveSummary/UnconfiguredApps/CrossDriveWarnings
  are always nil in the copy so the handler builds them fresh (fixes duplicate-apps bug)
- Replace binary IsMountPoint check with tiered CheckBackupDestination() — path-not-exist,
  not-writable, system-drive (warning), disk >90-95% full; shown as warning vs critical
- Remove dead settingsAppBackupHandler / POST /settings/app-backup route (toggle wrote
  to settings.json but nothing consumed the flag)

Architecture:
- Unified per-app backup rows: new AppBackupRow struct + buildAppBackupRows() replaces
  the two old sections with expandable rows showing all 3 layers per app
- Sequential backup chaining: cross-drive runs immediately after restic (removed
  independent cross-drive-daily/cross-drive-weekly scheduler jobs)
- Deploy page: remove "Csak kézi indítás" schedule option; add weekly consistency note

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

CHANGELOG.md

@@ -1,5 +1,16 @@
 ## Changelog
 
+### What was just completed (2026-02-17 session 37)
+- **v0.12.0 — Backup Page Overhaul — Unified App Backup Status & Bug Fixes:**
+  - **Bug Fix 1: Duplicate unconfigured apps** — `GetFullStatus()` now returns a deep copy of the cached status. `CrossDriveSummary`, `UnconfiguredApps`, and `CrossDriveWarnings` slices are always nil in the returned copy so the handler builds them fresh on every page load. Previously the handler appended to the cached slices, causing 3× duplication on 3 page loads.
+  - **Bug Fix 2: Misleading "drive disconnected" error** — Replaced the binary `IsMountPoint || !IsWritable` check with tiered `CheckBackupDestination()` validation (new in `internal/system/mounts_linux.go` and stub in `mounts_other.go`). Tiers: path doesn't exist (critical/blocked), not writable (critical/blocked), same block device as `/` (warning/allowed with note about system drive), disk >95% full (critical/blocked), disk >90% (warning/allowed). `isSameBlockDevice()` replaces `IsMountPoint()` for source/dest same-device detection. Used in both `deployHandler()` and `backupsHandler()` for display, and in `crossdrive.go` logic via `CheckBackupDestination()`.
+  - **Bug Fix 3: Dead BackupEnabled toggle** — Removed `settingsAppBackupHandler()` from handlers.go and its `POST /settings/app-backup` route from server.go. The toggle wrote to settings.json but nothing read it to skip apps. UI nightly backup section in deploy.html now shows an informational note instead of the toggle.
+  - **Architecture: Unified per-app backup rows** — New `AppBackupRow` struct and `buildAppBackupRows()` in handlers.go. Replaces old "Alkalmazás adatok" + "Másolatok másik meghajtóra" sections with a single expandable row per app showing all 3 backup layers (DB, Docker volumes, user data). Status dot: green=fully covered, yellow=warning (failed run, system drive, disk full), red=HDD data without cross-drive configured, auto=no user data. Expandable JS toggle with ▶/▼ icon.
+  - **Architecture: Sequential backup chaining** — Removed independent `cross-drive-daily` (03:30) and `cross-drive-weekly` (04:30) scheduler jobs. Cross-drive backups now run immediately after the restic backup completes (daily jobs every night; weekly jobs on Sunday). This ensures DB dump → restic → cross-drive happen in the same window for file/DB consistency on restore.
+  - **Architecture: Deploy page schedule dropdown** — Removed "Csak kézi indítás" option (schedule="manual"). Two options remain: "Naponta (az éjszakai mentés után)" and "Hetente, vasárnap (az éjszakai mentés után)". Weekly option shows informational note about DB consistency implications. Existing "manual" configs treated as "weekly" in the dropdown.
+  - **CSS added:** `.app-backup-row`, `.app-backup-row-header`, `.app-backup-row-name`, `.app-backup-row-meta`, `.app-backup-row-detail`, `.status-dot` (green/yellow/red/auto), `.backup-layers`, `.backup-layer-row`, `.layer-label`, `.layer-badge`, `.layer-na`, `.layer-method`, `.layer-dest`, `.layer-schedule`, `.layer-last`, `.layer-unconfigured`, `.layer-actions`, `.layer-warnings`, `.backup-layer-warning`, `.btn-xs`, `.text-ok`, `.text-error`.
+  - **Files modified (9):** `internal/backup/backup.go`, `internal/system/mounts_linux.go`, `internal/system/mounts_other.go`, `internal/web/handlers.go`, `internal/web/server.go`, `internal/web/templates/backups.html`, `internal/web/templates/deploy.html`, `internal/web/templates/style.css`, `cmd/controller/main.go`
+
 ### What was just completed (2026-02-17 session 36)
 - **v0.11.9 — UI Polish Fixes for deploy/settings backup section:**
   - **Fix 1: Spacing** — `.deploy-cross-drive` `margin-bottom` increased from `1rem` to `1.5rem` for consistent spacing before deploy form.