fix(dashboard): use runBdCmd for bd show routing in getIssueDetailsBatch

getIssueDetailsBatch was using runCmd for bd show, which doesn't set
cmd.Dir. This caused bd to use default routing instead of the town's
routes.jsonl, leading to dashboard slowness or missing data.

Use runBdCmd(f.townBeads, ...) to ensure proper database routing,
consistent with other bd commands in fetcher.go.

(gt-0v19)

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

internal/web/fetcher.go

@@ -81,7 +81,6 @@ func NewLiveConvoyFetcher() (*LiveConvoyFetcher, error) {
 	}, nil
 }
 
-
 // FetchConvoys fetches all open convoys with their activity data.
 func (f *LiveConvoyFetcher) FetchConvoys() ([]ConvoyRow, error) {
 	// List all open convoy-type issues
@@ -278,7 +277,7 @@ func (f *LiveConvoyFetcher) getIssueDetailsBatch(issueIDs []string) map[string]*
 	args := append([]string{"show"}, issueIDs...)
 	args = append(args, "--json")
 
-	stdout, err := runCmd(cmdTimeout, "bd", args...)
+	stdout, err := runBdCmd(f.townBeads, args...)
 	if err != nil {
 		return result
 	}