refactor: complete rewrite as React+FastAPI dashboard

Replace monolithic Jinja2 template with modern stack:

Backend (FastAPI):
- Modular router/service architecture
- Async PostgreSQL (asyncpg) for news from n8n pipeline
- Live Unraid server stats (2 servers via API)
- Home Assistant, Vikunja tasks, weather (wttr.in)
- WebSocket broadcast for real-time updates (15s)
- TTL cache per endpoint, all config via ENV vars

Frontend (React + Vite + TypeScript):
- Glassmorphism dark theme with Tailwind CSS
- Responsive grid: mobile/tablet/desktop/ultrawide
- Weather cards, hourly forecast, news with category tabs
- Server stats (CPU ring, RAM bar, Docker list)
- Home Assistant controls, task management
- Live clock, WebSocket connection indicator

Infrastructure:
- Multi-stage Dockerfile (node:22-alpine + python:3.11-slim)
- docker-compose with full ENV configuration
- Kaniko CI/CD pipeline for GitLab registry

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

.gitlab-ci.yml

@@ -11,7 +11,7 @@ docker-build:
     name: gcr.io/kaniko-project/executor:v1.23.2-debug
     entrypoint: [""]
   rules:
-    - if: $CI_COMMIT_BRANCH
+    - if: $CI_PIPELINE_SOURCE == "push" && $CI_COMMIT_BRANCH
   before_script:
     - mkdir -p /kaniko/.docker
     - |
@@ -27,14 +27,15 @@ docker-build:
       EOF
   script:
     - |
-      TAG="$CI_COMMIT_REF_SLUG"
-      DESTINATIONS="--destination=$IMAGE_NAME:$CI_COMMIT_SHA --destination=$IMAGE_NAME:$TAG"
-      if [ "$CI_COMMIT_REF_NAME" = "master" ]; then
-        DESTINATIONS="$DESTINATIONS --destination=$IMAGE_NAME:latest"
+      if [ "$CI_COMMIT_REF_NAME" = "main" ] || [ "$CI_COMMIT_REF_NAME" = "master" ]; then
+        TAG="latest"
+      else
+        TAG="$CI_COMMIT_REF_SLUG"
       fi
 
+      DESTINATIONS="--destination=$IMAGE_NAME:$CI_COMMIT_SHA --destination=$IMAGE_NAME:$TAG"
+
       echo "Building daily-briefing for ref $CI_COMMIT_REF_NAME with tag $TAG"
-      echo "Using registry image: $IMAGE_NAME"
 
       /kaniko/executor \
         --context "$CI_PROJECT_DIR" \