fix: resolve all critical runtime errors and bugs from audit

- Add COMPLETIONS_API_KEY to config.py (env var + auto-generated fallback)
- Fix perplexity auto-search: upstream sends logprobs=true, parse_llama_stream_chunk
  extracts per-token logprobs, all_logprobs populated during streaming
- Fix all /api/models endpoints to target LLAMA_SERVER_BASE (port 8081) not OLLAMA_BASE
- Fix RAG embedding endpoint URL from port 11434 (Ollama) to 8081 (llama-server)
- Correct misleading error messages: 'inference server' not 'Ollama'
- Remove raw_results leak from SSE event stream in /api/search
- Fix weather query extractor: pattern-match instead of unconditional suffix append
- Escape FTS5 operator keywords (AND/OR/NOT/NEAR) in memory search
- Move auth.py BODY_LIMIT_DEFAULT_BYTES imports to module level
- Change RAG injection log level from warning to info
- Fix all 8 test files after modular refactor (rewire imports from correct modules)
- Update AGENTS.md and README.md to reflect v1.8.0 changes

tests/test_auth_capabilities.py

@@ -3,16 +3,18 @@ from pathlib import Path
 
 from fastapi.testclient import TestClient
 
-import app as app_module
+import app
+import db
+from security import SESSIONS, PIN_ATTEMPTS
 
 
 def make_client(tmp_path: Path) -> TestClient:
     os.environ["JARVISCHAT_ADMIN_PIN"] = "1234"
-    app_module.DB_PATH = tmp_path / "jarvischat-test.db"
-    app_module.SESSIONS.clear()
-    app_module.PIN_ATTEMPTS.clear()
-    app_module.init_db()
-    return TestClient(app_module.app)
+    db.DB_PATH = tmp_path / "jarvischat-test.db"
+    SESSIONS.clear()
+    PIN_ATTEMPTS.clear()
+    db.init_db()
+    return TestClient(app.app)
 
 
 def test_guest_read_only_admin_write_blocked(tmp_path: Path):