Update Chunk

Update a chunk's content or metadata. Args: chunk_id: ID of the chunk to update request: UpdateChunkRequest with fields to update Returns: ChunkResponse with updated chunk Examples: Update chunk content: PATCH /chunks/chunk_123 { "content": "Updated chunk text" } Update chunk metadata: PATCH /chunks/chunk_123 { "metadata": { "category": "important", "tags": ["updated"] } } Update both content and metadata: PATCH /chunks/chunk_123 { "content": "Updated text", "metadata": {"status": "reviewed"} } Note: Updating chunk content will regenerate the embedding vector.