MCP server spawn failures were going to dbglog where the user
wouldn't see them. Route through the agent's notify so they appear
on the status bar.
Co-Authored-By: Proof of Concept <poc@bcachefs.org>
Duplicate key warnings fire on every store load and were writing to
stderr, corrupting the TUI display. Log write warnings and MCP
server failures are similarly routine. Route these to dbglog.
Serious errors (rkyv snapshot failures, store corruption) remain on
stderr — those are real problems the user needs to see.
Co-Authored-By: Proof of Concept <poc@bcachefs.org>
New mcp_client.rs: McpRegistry manages MCP server connections.
Spawns child processes, speaks JSON-RPC 2.0 over stdio. Discovers
tools via tools/list, dispatches calls via tools/call.
dispatch_with_agent falls through to MCP after checking internal
tools. McpRegistry lives on Agent (shared across forks).
Still needs: config-driven server startup, system prompt integration.
Co-Authored-By: Proof of Concept <poc@bcachefs.org>
