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>

.env.install

@@ -3,3 +3,5 @@ MYSQL_PORT=
 MYSQL_DATABASE=
 MYSQL_USER=
 MYSQL_PASSWORD=
+STL_UPLOAD_DIR=/data/stl
+TZ=Europe/Berlin