feat(deployment): update Semaphore stack and Traefik configuration

- Add QUICKSTART.md and SETUP_REPOSITORY.md for Semaphore stack
- Add playbooks directory for Semaphore deployment
- Update Semaphore docker-compose.yml, env.example, and README
- Add Traefik local configuration files
- Disable semaphore.yml in Traefik dynamic config
- Update docker-compose.local.yml and build-image workflow

deployment/stacks/traefik/dynamic/semaphore.yml.disabled

@@ -0,0 +1,17 @@
+http:
+  routers:
+    semaphore:
+      rule: Host(`semaphore.michaelschiemer.de`)
+      entrypoints:
+        - websecure
+      service: semaphore
+      tls:
+        certResolver: letsencrypt
+      priority: 100
+  services:
+    semaphore:
+      loadBalancer:
+        # Use localhost port binding since Semaphore binds to 127.0.0.1
+        # Port is configured via SEMAPHORE_PORT in .env (currently 9300)
+        servers:
+          - url: http://127.0.0.1:9300