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>

static/style.css

@@ -272,7 +272,9 @@ a:hover { color: var(--orange); }
 }
 .mc-chat-panel > .card {
   height: 100%;
-  overflow: clip;
+  min-height: 0;            /* flex child: allow shrink below content */
+  margin-bottom: 0;         /* override Bootstrap .card margin that breaks flex sizing */
+  overflow: hidden;
 }
 
 /* ── Panel / Card overrides ──────────────────────── */
@@ -396,6 +398,7 @@ a:hover { color: var(--orange); }
 /* ── Chat ────────────────────────────────────────── */
 .chat-log {
   flex: 1;
+  min-height: 0;            /* allow flex child to shrink below content height */
   overflow-y: auto;
   -webkit-overflow-scrolling: touch;
 }