Add job creation with UUID, STL upload/library, search, job log, TZ, and CLAUDE.md

- PrintJob: job_uuid (UUID4), customer, logs relationship
- JobLog model + migration 0004 (also includes job_logs table)
- POST /jobs: upload STL or select from library, auto-logs 'Job created'
- GET /jobs?q=: search by customer or filename across all statuses
- app/stl.py: STL_UPLOAD_DIR helper (from env, default /data/stl)
- docker-compose: named volume stl_files mounted at /data/stl
- .env.install: added STL_UPLOAD_DIR and TZ=Europe/Berlin
- CLAUDE.md: full project context for future sessions

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

docker-compose.yml

@@ -4,4 +4,9 @@ services:
     ports:
       - "8720:8720"
     env_file: .env
+    volumes:
+      - stl_files:/data/stl
     restart: unless-stopped
+
+volumes:
+  stl_files: