bug(mcp): MCP tool operations are not logged to request_logs table #68

Describe the bug

MCP tool operations (add_memory, search_memory, list_memories, update_memory, delete_memory) are not recorded in the request_logs table, while HTTP API requests (via the web dashboard) are.

This means the "Requests" page in the web UI (crates/memayu-web/src/pages/requests.rs) shows no entries when memories are written/read through the MCP server — only HTTP API calls are visible.

Steps to reproduce

1. Start memayu serve and connect an MCP client (e.g. an stdio MCP client pointing at the memayu mcp transport).
2. Call any MCP tool (e.g. add_memory).
3. Open the web UI → Requests page, or query the request_logs table directly.
4. Observe: no rows for the MCP operation.

Expected behavior

MCP tool calls should be logged to request_logs (e.g. method = MCP, path = mcp/<tool_name>, with status + latency + auth) just like HTTP API requests, so the audit log / Requests page is complete regardless of access path.

Root cause (source inspection on main, v0.1.0 line)

• crates/memayu-api/src/transport/routes.rs calls request_log_insert(...) after HTTP responses.
• crates/memayu-mcp/src/tools/*.rs (add_memory.rs, search_memory.rs, etc.) call backend.add_memory() / backend.search_memory() directly and never call request_log_insert.
• The memayu-mcp crate has zero references to request_log.

Suggested fix

Add request_log_insert calls (or a shared MCP transport middleware/wrapper) in the MCP tool handlers, mirroring the HTTP API's logging. Use a synthetic method/path like MCP / mcp/<tool_name> so the Requests page can distinguish the transport.

Environment

• memayu v0.1.0 (aarch64-unknown-linux-gnu release binary)
• Local Candle embedder (dim 384)
• Reproduced on Raspberry Pi 4 + macOS client

Context

• Discovered while reviewing PRs feat(cli): improve cli setup wizard #58–chore(docs): add systemd service example, docker-compose, and troubleshooting (#49) #65. The Requests page was implemented in PR feat(cli): improve cli setup wizard #58 (crates/memayu-web/src/pages/requests.rs) but logging was never extended to the MCP transport.