Slice 6: right-click command menu + git write actions

git boundary: Pull/Push/Commit/DiscardAll (discard is 1.4-destructive). Scanner.RefreshRepo re-scans one repo after a mutation. Service GitFetch/GitPull/GitPush/GitCommit/GitDiscard record a git-* activity event and refresh on success; service.New takes a refresh hook. HTTP POST /api/repo/git. New <repo-menu> overlay with plain-language commands (Get latest/Publish/Check for updates/Save my work/Set active/Ask Claude to switch/Copy path/Discard all changes), summoned by repo-list's repo:contextmenu. Added service test for commit/discard on a temp repo. Verified the menu live for safe commands.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

internal/repos/repos.go

@@ -122,6 +122,13 @@ func (s *Scanner) Refresh(ctx context.Context) {
 	}
 }
 
+// RefreshRepo re-scans a single repository and updates the index. Used after a
+// mutating action so the UI reflects the new state without waiting for the next
+// full scan.
+func (s *Scanner) RefreshRepo(ctx context.Context, path string) {
+	s.Index.set(s.refreshOne(ctx, path))
+}
+
 func (s *Scanner) refreshOne(ctx context.Context, path string) State {
 	rctx, cancel := context.WithTimeout(ctx, 20*time.Second)
 	defer cancel()