fix: ChatContext is not a sequence — use .items for len/list; add test suite

Bug fix:
- GemmaLLM.chat(): len(chat_ctx) → len(chat_ctx.items)
- GemmaLLM._compact_context(): list(chat_ctx) → list(chat_ctx.items)
  ChatContext in livekit-agents 1.7 is not iterable or sized directly;
  it exposes an .items list. The TypeError was silently killing all LLM
  responses (agent heard user but never spoke back).

Test suite (tests/):
- test_web_ui.py: static assets, token endpoint, LiveKit WS proxy
- test_llm_api.py: completion, tool calling, thinking-disabled latency, streaming
- test_mcp_tools.py: weather (Fahrenheit), time, memory, skills — all via
  docker exec + in-container MCP client
- test_agent_integration.py: process alive, worker registered, supervisord,
  container health, LiveKit API
- test_compaction.py: size-triggered compaction, system prompt preservation,
  short-context no-op
- conftest.py: shared fixtures (HTTPS client, token, LLM, docker exec helpers)
- Run with: .venv-tests/bin/python -m pytest tests/ -v

tests/test_web_ui.py

@@ -0,0 +1,74 @@
+"""Tests for the web UI served by nginx (HTTPS :8090) and the token endpoint."""
+
+import json
+
+import httpx
+
+
+def test_index_serves(client):
+    resp = client.get("/")
+    assert resp.status_code == 200
+    body = resp.text
+    assert "Hope" in body
+    assert "livekit-client.umd.js" in body
+    assert "app.js" in body
+
+
+def test_app_js_serves(client):
+    resp = client.get("/app.js")
+    assert resp.status_code == 200
+    assert "LiveKitClient" in resp.text or "Room" in resp.text
+
+
+def test_style_css_serves(client):
+    resp = client.get("/style.css")
+    assert resp.status_code == 200
+    body = resp.text
+    assert "{" in body and "}" in body
+    assert "color" in body or "background" in body
+
+
+def test_manifest_serves(client):
+    resp = client.get("/manifest.json")
+    assert resp.status_code == 200
+    manifest = json.loads(resp.text)
+    assert "name" in manifest
+
+
+def test_favicon_serves(client):
+    resp = client.get("/favicon.svg")
+    assert resp.status_code == 200
+    assert "svg" in resp.headers.get("content-type", "")
+    assert "<svg" in resp.text
+
+
+def test_livekit_client_bundle_serves(client):
+    resp = client.get("/livekit-client.umd.js")
+    assert resp.status_code == 200
+    assert len(resp.text) > 100_000  # vendored UMD bundle is large
+
+
+def test_token_endpoint_direct():
+    """Token server on 127.0.0.1:8091 (host network mode)."""
+    resp = httpx.post("http://127.0.0.1:8091/token", json={}, timeout=10)
+    assert resp.status_code == 200
+    data = resp.json()
+    assert "token" in data and data["token"].count(".") == 2  # JWT shape
+
+
+def test_token_endpoint_via_nginx(client):
+    """nginx proxies /token to the token server."""
+    resp = client.post("/token", json={})
+    assert resp.status_code == 200
+    data = resp.json()
+    assert "token" in data and data["token"].count(".") == 2
+
+
+def test_livekit_ws_proxy(client):
+    """The /livekit/ path is proxied to the LiveKit server (HTTP :7880)."""
+    resp = client.get("/livekit/")
+    # LiveKit's HTTP API answers on /; a 200 or an API error JSON both prove
+    # the proxy reaches the LiveKit server rather than nginx serving statics.
+    assert resp.status_code in (200, 404, 405)
+    if resp.headers.get("content-type", "").startswith("application/json"):
+        json.loads(resp.text)