fix: add timeout to daemon request context to prevent indefinite hangs

reqCtx() now applies the server's requestTimeout (default 30s) to the
context returned for request handlers. This prevents bd list and other
commands from hanging indefinitely when database operations stall.

The fix ensures:
- All RPC handlers get a context with a deadline
- Database operations (using QueryContext) honor context cancellation
- reconnectMu read locks are released when context times out

Fixes: bd-p76kv

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Executed-By: beads/crew/dave
Rig: beads
Role: crew

internal/rpc/server_routing_validation_diagnostics.go

@@ -259,8 +259,13 @@ func (s *Server) handleRequest(req *Request) Response {
 }
 
 // Adapter helpers
+
+// reqCtx returns a context with the server's request timeout applied.
+// This prevents request handlers from hanging indefinitely if database
+// operations or other internal calls stall (GH#bd-p76kv).
 func (s *Server) reqCtx(_ *Request) context.Context {
-	return context.Background()
+	ctx, _ := context.WithTimeout(context.Background(), s.requestTimeout)
+	return ctx
 }
 
 func (s *Server) reqActor(req *Request) string {