Add MCP server, note mutation endpoint, and updated_at tracking (v3.0.0)

New MCP server (mcp/) exposes kb operations as native MCP tools over
Streamable HTTP with Bearer token auth. Supports collections via tag
conventions, chunked file uploads, and agent-side search patterns.

Engine gains PATCH /api/v1/notes/{id} for in-place note updates with
transactional re-chunk/re-embed, and updated_at column on documents.

Go client adds updatenote command and Patch HTTP method.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

mcp/engine.py

@@ -0,0 +1,121 @@
+"""HTTP client for the kb engine API."""
+
+import httpx
+
+from config import KB_ENGINE_URL, KB_API_KEY
+
+
+def _auth_headers() -> dict[str, str]:
+    h: dict[str, str] = {}
+    if KB_API_KEY:
+        h["Authorization"] = f"Bearer {KB_API_KEY}"
+    return h
+
+
+def _client() -> httpx.Client:
+    return httpx.Client(base_url=KB_ENGINE_URL, headers=_auth_headers(), timeout=60.0)
+
+
+def search(query: str, top: int = 10, tags: list[str] | None = None,
+           doc_type: str | None = None, fts_only: bool = False,
+           vec_only: bool = False, threshold: float | None = None) -> dict:
+    body: dict = {"query": query, "top": top}
+    if tags:
+        body["tags"] = tags
+    if doc_type:
+        body["doc_type"] = doc_type
+    if fts_only:
+        body["fts_only"] = True
+    if vec_only:
+        body["vec_only"] = True
+    if threshold is not None:
+        body["threshold"] = threshold
+    with _client() as c:
+        r = c.post("/api/v1/search", json=body)
+        r.raise_for_status()
+        return r.json()
+
+
+def add_note(text: str, tags: list[str] | None = None,
+             title: str | None = None) -> dict:
+    fields = {"note": text}
+    if tags:
+        fields["tags"] = ",".join(tags)
+    if title:
+        fields["title"] = title
+    with _client() as c:
+        r = c.post("/api/v1/jobs", data=fields)
+        r.raise_for_status()
+        return r.json()
+
+
+def update_note(doc_id: int, text: str) -> dict:
+    with _client() as c:
+        r = c.patch(f"/api/v1/notes/{doc_id}", json={"text": text})
+        r.raise_for_status()
+        return r.json()
+
+
+def get_document(doc_id: int) -> dict:
+    with _client() as c:
+        r = c.get(f"/api/v1/documents/{doc_id}")
+        r.raise_for_status()
+        return r.json()
+
+
+def list_documents(doc_type: str | None = None,
+                   tags: str | None = None) -> list[dict]:
+    params: dict = {}
+    if doc_type:
+        params["type"] = doc_type
+    if tags:
+        params["tags"] = tags
+    with _client() as c:
+        r = c.get("/api/v1/documents", params=params)
+        r.raise_for_status()
+        return r.json()
+
+
+def get_status() -> dict:
+    with _client() as c:
+        r = c.get("/api/v1/status")
+        r.raise_for_status()
+        return r.json()
+
+
+def list_jobs(status: str | None = None) -> list[dict]:
+    params: dict = {}
+    if status:
+        params["status"] = status
+    with _client() as c:
+        r = c.get("/api/v1/jobs", params=params)
+        r.raise_for_status()
+        return r.json()
+
+
+def update_tags(doc_id: int, add: list[str] | None = None,
+                remove: list[str] | None = None) -> dict:
+    body: dict = {}
+    if add:
+        body["add"] = add
+    if remove:
+        body["remove"] = remove
+    with _client() as c:
+        r = c.put(f"/api/v1/documents/{doc_id}/tags", json=body)
+        r.raise_for_status()
+        return r.json()
+
+
+def upload_file(filename: str, file_bytes: bytes,
+                tags: list[str] | None = None) -> dict:
+    fields: dict = {}
+    if tags:
+        fields["tags"] = ",".join(tags)
+    with _client() as c:
+        r = c.post(
+            "/api/v1/jobs",
+            data=fields,
+            files={"file": (filename, file_bytes)},
+        )
+        r.raise_for_status()
+        return r.json()