fix(ci): mock AI provider in record_decision test + cache pip/npm + drop term-missing

Three changes that get PR #150 to a green CI gate:

1. **test_record_decision_persists_and_bumps_state_version** — the
   `decision: draft_template` path calls `_extract_template_parameters`
   (TemplateExtractionService → AI provider). CI doesn't set
   ANTHROPIC_API_KEY/GOOGLE_AI_API_KEY, so the endpoint raised
   `RuntimeError: No AI provider configured` and returned 500. The test
   isn't exercising the AI integration — patched the extractor with an
   AsyncMock returning a minimal valid `{templated_body, parameters}`
   dict. Verified locally: the test now passes.

2. **pip + npm caches** in backend, frontend, and e2e jobs. Keyed on
   the hash of requirements*.txt / package-lock.json with a runner-os
   restore-key fallback. Saves ~30-60s per run on cache hit.

3. **Pytest invocation tightened**:
   - Dropped `--cov-report=term-missing` — the custom "Display coverage
     summary" step below parses coverage.json and prints the same
     module list more concisely. Term-missing dumps every uncovered
     line which adds ~5-10s of stdout.
   - Added `--maxfail=10` so a structural breakage (fixture explosion,
     DB unreachable) bails after 10 errors instead of running the full
     25-min suite. Tunable.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

backend/tests/test_session_suggested_fixes_api.py

@@ -218,11 +218,23 @@ async def test_record_decision_persists_and_bumps_state_version(
     test_db.add(fix)
     await test_db.commit()
 
-    r = await client.post(
-        f"/api/v1/ai-sessions/{session.id}/suggested-fixes/{fix.id}/decision",
-        headers=auth_headers,
-        json={"decision": "draft_template"},
-    )
+    # The draft_template path calls TemplateExtractionService, which needs an
+    # AI provider configured. CI doesn't set ANTHROPIC_API_KEY/GOOGLE_AI_API_KEY,
+    # and this test isn't exercising the AI integration — patch the extractor
+    # with a minimal valid response so the rest of the decision flow runs.
+    extractor_stub = AsyncMock(return_value={
+        "templated_body": "Write-Output 'ok'",
+        "parameters": [],
+    })
+    with patch(
+        "app.api.endpoints.session_suggested_fixes._extract_template_parameters",
+        extractor_stub,
+    ):
+        r = await client.post(
+            f"/api/v1/ai-sessions/{session.id}/suggested-fixes/{fix.id}/decision",
+            headers=auth_headers,
+            json={"decision": "draft_template"},
+        )
     assert r.status_code == 200
     assert r.json()["user_decision"] == "draft_template"