test: add unit tests for all 10 routers (92 total)

New test files:
- test_conversations.py — list/create/get/update/delete/delete-all, admin enforcement
- test_presets.py — list/create/update/delete, default preset protection
- test_profile.py — get/update/default, length validation
- test_models_router.py — list/ps/show/stats/search-status, connect errors
- test_completions.py — API key auth, FIM passthrough, streaming/blocking, errors
- test_search_route.py — explicit search flow, no results, stream errors
- test_memories.py — edit/search/stats endpoints, validation, admin enforcement

Update AGENTS.md with full test file coverage table and README.md

tests/test_profile.py

@@ -0,0 +1,72 @@
+import os
+from pathlib import Path
+
+from fastapi.testclient import TestClient
+
+import app
+import config
+import db
+from security import SESSIONS, PIN_ATTEMPTS, RATE_EVENTS
+
+
+def make_client(tmp_path: Path) -> TestClient:
+    os.environ["JARVISCHAT_ADMIN_PIN"] = "1234"
+    db.DB_PATH = tmp_path / "jarvischat-profile.db"
+    SESSIONS.clear()
+    PIN_ATTEMPTS.clear()
+    RATE_EVENTS.clear()
+    db.init_db()
+    return TestClient(app.app, raise_server_exceptions=False)
+
+
+def _admin_headers(client: TestClient) -> dict:
+    login = client.post("/api/auth/login", json={"pin": "1234"}, headers={"Origin": "http://testserver"})
+    sid = login.json()["session_id"]
+    return {"X-Session-ID": sid, "Origin": "http://testserver"}
+
+
+def _guest_headers(client: TestClient) -> dict:
+    sid = client.post("/api/auth/guest", headers={"Origin": "http://testserver"}).json()["session_id"]
+    return {"X-Session-ID": sid, "Origin": "http://testserver"}
+
+
+def test_get_profile_returns_content(tmp_path: Path):
+    with make_client(tmp_path) as client:
+        resp = client.get("/api/profile", headers=_guest_headers(client))
+        assert resp.status_code == 200
+        data = resp.json()
+        assert "content" in data
+        assert "updated_at" in data
+        assert len(data["content"]) > 0
+
+
+def test_get_default_profile(tmp_path: Path):
+    with make_client(tmp_path) as client:
+        resp = client.get("/api/profile/default", headers=_guest_headers(client))
+        assert resp.status_code == 200
+        assert resp.json()["content"] == config.DEFAULT_PROFILE
+
+
+def test_update_profile(tmp_path: Path):
+    with make_client(tmp_path) as client:
+        headers = _admin_headers(client)
+        resp = client.put("/api/profile", json={"content": "Custom profile text."}, headers=headers)
+        assert resp.status_code == 200
+        assert "updated_at" in resp.json()
+
+        get_resp = client.get("/api/profile", headers=_guest_headers(client))
+        assert get_resp.json()["content"] == "Custom profile text."
+
+
+def test_update_profile_too_long(tmp_path: Path):
+    with make_client(tmp_path) as client:
+        headers = _admin_headers(client)
+        long_content = "x" * (config.MAX_PROFILE_CHARS + 1)
+        resp = client.put("/api/profile", json={"content": long_content}, headers=headers)
+        assert resp.status_code == 413
+
+
+def test_guest_cannot_update_profile(tmp_path: Path):
+    with make_client(tmp_path) as client:
+        resp = client.put("/api/profile", json={"content": "hack"}, headers=_guest_headers(client))
+        assert resp.status_code == 403