feat(cli): add --timings flag and enrich error tracking fields

Add -t/--timings flag to the sync subcommand, allowing users to opt
into a per-stage timing breakdown after the sync summary. Wire the flag
through main.rs into print_sync() which passes it to the new
should_print_timings() gate.

Enrich the data structures that flow through the sync pipeline so
downstream renderers have full error visibility:

- ProjectSummary gains status_errors (issue-side status enrichment
  failures per project)
- ProjectStatusEnrichment gains path (project path for sub-row display)
- SyncResult gains documents_errored and embedding_failed so the
  summary can surface doc-gen and embed failures separately
- Autocorrect table updated with --timings for fuzzy flag matching

src/cli/autocorrect.rs

@@ -126,6 +126,7 @@ const COMMAND_FLAGS: &[(&str, &[&str])] = &[
             "--no-file-changes",
             "--dry-run",
             "--no-dry-run",
+            "--timings",
         ],
     ),
     (