The desktop app and dashboard chat reach the agent through the /api/ws
JSON-RPC sidecar (tui_gateway.ws.handle_ws), NOT through
tui_gateway.entry.main() — the stdio-TUI path that spawns the background
MCP discovery thread. In the WS process discovery was therefore never
started: _make_agent only *waits* (wait_for_mcp_discovery), which no-ops
when the thread was never created, so the agent snapshotted an MCP-less
tool list. The only discovery trigger reachable was a manual /reload-mcp,
which is why tools appeared after a reload but vanished on restart.
Start the shared, idempotent, config-gated background discovery in
handle_ws right after accept() and before gateway.ready, so the first
agent build picks up already-spawning servers (and the existing
late-binding refresh handles slow ones).
Fixes#38945.
5c2c85c545