chore(infra): remove night-scheduler service entirely [guardrail-change]

Deletes the night-scheduler (nightly auto-shutdown of services). It stopped
services at 22:00 and killed long-running jobs (e.g. bulk embedding) — net
hindrance. Removed: running container, compose service + hetzner override,
source dir, CI lint entry, rule doc.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

.gitea/workflows/ci.yaml

@@ -3,7 +3,7 @@
 #
 # Services:
 #   Go: consent-service
-#   Python: backend-core, voice-service (+ BQAS), embedding-service, night-scheduler
+#   Python: backend-core, voice-service (+ BQAS), embedding-service
 #   Node.js: admin-core
 
 name: CI
@@ -46,7 +46,7 @@ jobs:
       - name: Lint Python services
         run: |
           pip install --quiet ruff
-          for svc in backend-core voice-service night-scheduler embedding-service; do
+          for svc in backend-core voice-service embedding-service; do
             if [ -d "$svc" ]; then
               echo "=== Linting $svc ==="
               ruff check "$svc/" --output-format=github || true