feat: add Ressourcen timeline view with group ordering (alpha.14)

- New timeline page showing all groups and active events in parallel
- Group order API endpoints with persistence (GET/POST /api/groups/order)
- Customizable group ordering with visual controls
- Fix CSS and TypeScript lint errors
- Update documentation and bump version to 2026.1.0-alpha.14

.github/copilot-instructions.md

@@ -28,9 +28,12 @@ Keep docs synced with code. When you change services/MQTT/API/UTC/env or dev/pro
 - `scheduler/scheduler.py` — scheduler main loop and MQTT publisher
 - `server/routes/eventmedia.py` — file uploads, streaming endpoint
 - `server/routes/events.py` — event CRUD and recurrence handling
+- `server/routes/groups.py` — group management, alive status, display order persistence
 - `dashboard/src/components/CustomEventModal.tsx` — event creation UI
 - `dashboard/src/media.tsx` — FileManager / upload settings
- - `dashboard/src/settings.tsx` — settings UI (nested tabs; system defaults for presentations and videos)
+- `dashboard/src/settings.tsx` — settings UI (nested tabs; system defaults for presentations and videos)
+- `dashboard/src/ressourcen.tsx` — timeline view showing all groups' active events in parallel
+- `dashboard/src/ressourcen.css` — timeline and resource view styling
 
 
 
@@ -51,7 +54,21 @@ Keep docs synced with code. When you change services/MQTT/API/UTC/env or dev/pro
 
   ## Recent changes since last commit
 
-  ### Latest (November 2025)
+  ### Latest (January 2026)
+  
+  - **Ressourcen Page (Timeline View)**:
+    - New 'Ressourcen' page with parallel timeline view showing active events for all room groups
+    - Compact timeline display with adjustable row height (65px per group)
+    - Real-time view of currently running events with type, title, and time window
+    - Customizable group ordering with visual reordering panel (drag up/down buttons)
+    - Group order persisted via `GET/POST /api/groups/order` endpoints
+    - Color-coded event bars matching group theme
+    - Timeline modes: Day and Week views (day view by default)
+    - Dynamic height calculation based on number of groups
+    - Syncfusion ScheduleComponent with TimelineViews, Resize, and DragAndDrop support
+    - Files: `dashboard/src/ressourcen.tsx` (page), `dashboard/src/ressourcen.css` (styles)
+
+  ### Earlier (November 2025)
   
   - **API Naming Convention Standardization (camelCase)**:
     - Backend: Created `server/serializers.py` with `dict_to_camel_case()` utility for consistent JSON serialization
@@ -155,8 +172,8 @@ Keep docs synced with code. When you change services/MQTT/API/UTC/env or dev/pro
 - Session usage: instantiate `Session()` per request, commit when mutating, and always `session.close()` before returning.
 - Examples:
   - Clients: `server/routes/clients.py` includes bulk group updates and MQTT sync (`publish_multiple_client_groups`).
-  - Groups: `server/routes/groups.py` computes “alive” using a grace period that varies by `ENV`.
-  - Events: `server/routes/events.py` serializes enum values to strings and normalizes times to UTC. Recurring events are only deactivated after their recurrence_end (UNTIL); non-recurring events deactivate after their end time. Event exceptions are respected and rendered in scheduler output.
+  - Groups: `server/routes/groups.py` computes “alive” using a grace period that varies by `ENV`.    - `GET /api/groups/order` — retrieve saved group display order
+    - `POST /api/groups/order` — persist group display order (array of group IDs)  - Events: `server/routes/events.py` serializes enum values to strings and normalizes times to UTC. Recurring events are only deactivated after their recurrence_end (UNTIL); non-recurring events deactivate after their end time. Event exceptions are respected and rendered in scheduler output.
   - Media: `server/routes/eventmedia.py` implements a simple file manager API rooted at `server/media/`.
   - System settings: `server/routes/system_settings.py` exposes key–value CRUD (`/api/system-settings`) and a convenience endpoint for WebUntis/Vertretungsplan supplement-table: `GET/POST /api/system-settings/supplement-table` (admin+).
   - Academic periods: `server/routes/academic_periods.py` exposes:
@@ -264,6 +281,18 @@ Keep docs synced with code. When you change services/MQTT/API/UTC/env or dev/pro
   - Auto-refresh every 15 seconds; manual refresh button available
   - "Nicht zugeordnet" group always appears last in sorted list
 
+- Ressourcen page (`dashboard/src/ressourcen.tsx`):
+  - Timeline view showing all groups and their active events in parallel
+  - Uses Syncfusion ScheduleComponent with TimelineViews (day/week modes)
+  - Compact row display: 65px height per group, dynamically calculated total height
+  - Group ordering panel with drag up/down controls; order persisted to backend via `/api/groups/order`
+  - Filters out "Nicht zugeordnet" group from timeline display
+  - Fetches events per group for current date range; displays first active event per group
+  - Color-coded event bars using `getGroupColor()` from `groupColors.ts`
+  - Resource-based timeline: each group is a resource row, events mapped to `ResourceId`
+  - Real-time updates: loads events on mount and when view/date changes
+  - Custom CSS in `dashboard/src/ressourcen.css` for timeline styling and controls
+
 - User dropdown technical notes:
   - Dependencies: `@syncfusion/ej2-react-splitbuttons` and `@syncfusion/ej2-splitbuttons` must be installed.
   - Vite: add both to `optimizeDeps.include` in `vite.config.ts` to avoid import-analysis errors.