feat: single-command Docker startup, fix UI bugs, add Selenium tests

- Add `make up` / `make up DEV=1` for one-command Docker startup with
  optional hot-reload via docker-compose.dev.yml overlay
- Add `timmy up --dev` / `timmy down` CLI commands
- Fix cross-platform font resolution in creative assembler (7 test failures)
- Fix Ollama host URL not passed to Agno model (container connectivity)
- Fix task panel route shadowing by reordering literal routes before
  parameterized routes in swarm.py
- Fix chat input not clearing after send (hx-on::after-request)
- Fix chat scroll overflow (CSS min-height: 0 on flex children)
- Add Selenium UI smoke tests (17 tests, gated behind SELENIUM_UI=1)
- Install fonts-dejavu-core in Dockerfile for container font support
- Remove obsolete docker-compose version key
- Bump CSS cache-bust to v4

833 unit tests pass, 15 Selenium tests pass (2 skipped).

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

docker-compose.yml

@@ -15,8 +15,6 @@
 #   make docker-down     stop everything
 #   make docker-logs     tail logs
 
-version: "3.9"
-
 services:
 
   # ── Dashboard (coordinator + FastAPI) ──────────────────────────────────────