v0.25.0 — Debug page: operator testing & diagnostics dashboard

Debug-mode-only dashboard (/debug) with 8 collapsible sections:
system diagnostics, notification testing, backup triggers, storage
simulation, hub & connectivity, self-update dry-run, DR/setup wizard,
and in-memory log viewer. Migrates debug dump from API router to web
server. Adds ring buffer log capture, storage disconnect simulation,
event history tracking, and cross-drive/self-update test methods.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

controller/README.md

@@ -4,7 +4,7 @@
 
 A single, lightweight Go container that replaces Portainer + scattered systemd scripts with a unified, Hungarian-language web dashboard for managing Docker Compose stacks, backups, storage, monitoring, and notifications on customer hardware.
 
-**Current version: v0.24.0**
+**Current version: v0.25.0**
 
 ---
 
@@ -23,6 +23,7 @@ A single, lightweight Go container that replaces Portainer + scattered systemd s
   - [Setup Wizard](#9-first-run-setup-wizard)
   - [Disaster Recovery](#10-disaster-recovery)
   - [Asset Sync](#11-asset-sync)
+  - [Debug Mode](#12-debug-mode)
 - [Repository Layout](#repository-layout)
 - [Configuration](#configuration)
 - [REST API](#rest-api)
@@ -993,6 +994,33 @@ The Hub serves three asset types per app:
 
 ---
 
+### 12. Debug Mode
+
+When `logging.level: "debug"` is set in `controller.yaml`, the controller exposes a full diagnostic dashboard at `/debug` with 8 testing sections. All debug endpoints are gated — at `info` level, the sidebar link disappears and all `/api/debug/*` routes return 404.
+
+#### Debug Page Sections
+
+| # | Section | Endpoints | Description |
+|---|---------|-----------|-------------|
+| 1 | Rendszer diagnosztika | `GET /api/debug/dump` | Full state dump: controller info, storage, stacks, scheduler, health, alerts. JSON download. |
+| 2 | Értesítés teszt | `POST /api/debug/event/test`, `GET /api/debug/event/history` | Send test events with configurable type/severity, view event history ring buffer. |
+| 3 | Mentés teszt | `POST /api/debug/backup/{dbdump,crossdrive,integrity,infra}` | Trigger individual backup phases independently. |
+| 4 | Tárhely teszt | `POST /api/debug/storage/simulate-{disconnect,reconnect}`, `GET /api/debug/storage/watchdog-status` | Simulate drive disconnect/reconnect without unmounting. Per-path probe state with 5s auto-refresh. |
+| 5 | Hub & Kapcsolatok | `POST /api/debug/hub/{push,infra-push,test-connectivity,preferences-sync}`, `POST /api/debug/gitea/test-connectivity` | Test Hub/Gitea connectivity with latency. Push reports and sync preferences. |
+| 6 | Önfrissítés teszt | `POST /api/debug/selfupdate/dry-run` | Dry-run update check: current vs new image lines, compose writability, backup state. |
+| 7 | DR / Telepítő varázsló | `POST /api/debug/dr/trigger-setup`, `GET /api/debug/dr/infra-status` | Infra backup status per drive. Trigger setup mode via marker file (requires "RESET" + infra backup pre-check). |
+| 8 | Naplóviewer | `GET /api/debug/logs?level=&limit=&after=` | In-memory log viewer (last 1000 entries), level filter, 2s auto-refresh, color-coded entries. |
+
+#### Key Implementation Details
+
+- **Log buffer** (`internal/web/logbuffer.go`): Ring buffer implementing `io.Writer`, created before all modules via `io.MultiWriter(os.Stdout, logBuffer)`. Parses `[DEBUG]`/`[INFO]`/`[WARN]`/`[ERROR]` tags from standard log format.
+- **Storage simulation**: `simulatedPaths` map in watchdog prevents the watchdog from re-probing simulated-disconnected paths. Disconnect runs all real steps except `lazyUnmount` (drive stays physically mounted).
+- **DR trigger safety**: Uses marker file (`data/.needs-setup`) instead of modifying controller.yaml. Pre-checks that infra backup exists on at least one drive.
+- **Routing**: `/api/debug/` carved out in HTTP mux (same pattern as `/api/storage/`), routed to web server with auth + CSRF.
+- **DebugCallbacks**: 6 closures wired from main.go for operations needing modules not on Server struct (hub push, infra backup, connectivity tests).
+
+---
+
 ## Repository Layout
 
 ```
@@ -1064,11 +1092,13 @@ controller/
 │       ├── csrf.go                 # CsrfProtect middleware, csrfToken/csrfField helpers
 │       ├── handlers.go             # Page handlers (dashboard, stacks, deploy, backups, etc.)
 │       ├── handler_restore.go      # DR: restore page handler + APIs (scan, restore all, skip)
+│       ├── handler_debug.go        # Debug page handler + 20 debug API endpoints (debug-mode only)
+│       ├── logbuffer.go            # Ring buffer (io.Writer) for in-memory log capture
 │       ├── storage_handlers.go     # Storage API handlers (scan, format, attach, migrate, cleanup, disconnect/reconnect)
 │       ├── alerts.go               # State-based alert generation
 │       ├── funcmap.go              # Template functions (state colors, Hungarian formatting)
 │       ├── embed.go                # go:embed for templates + Chart.js
-│       └── templates/              # 13 HTML files + style.css (Hungarian UI)
+│       └── templates/              # 14 HTML files + style.css (Hungarian UI, incl. debug.html)
 ├── configs/
 │   ├── controller.yaml.example     # Full config reference
 │   └── example-felhom-metadata.yml # .felhom.yml format reference