fix review findings: CI leaf-gate wiring, heritage return surface, AGENTS.md self-containedness

- run-gates.ts docSyncLeafGates() gains verify-export-jsdoc — CI lanes
  and the pre-push hook execute this leaf list, not the doc-sync npm
  script, so the gate was previously unenforced there (proven by
  SessionForkErrorCode landing undocumented via a master merge while
  checks stayed green; now documented). Same wiring gap fixed for
  master's verify-config-catalog, which was also missing from the list.
- The heritage exemption now recovers the base's return surface: a void
  base return carried no @returns duty, so an override returning a
  concrete result documents it itself (annotated overrides run the
  standard check; unannotated ones are classified by the checker so
  faithful void overrides need no boilerplate annotation). Three new
  negative-path tests pin it; RFC and module doc updated.
- AGENTS.md states each principle inline instead of citing RFCs (eight
  citations removed; high-level doc links kept) and the editing section
  now carries the self-containedness rule.
- Generated catalogs/graphs regenerated for the shifted line pointers.

scripts/run-gates.ts

@@ -257,7 +257,9 @@ function docSyncLeafGates(): Gate[] {
   return [
     pnpmScript('doc-typecheck', 'doc-typecheck'),
     pnpmScript('cordis-catalog', 'verify-cordis-catalog', { label: 'cordis catalog' }),
+    pnpmScript('export-jsdoc', 'verify-export-jsdoc', { label: 'export jsdoc' }),
     pnpmScript('tool-catalog', 'verify-tool-catalog', { label: 'tool catalog' }),
+    pnpmScript('config-catalog', 'verify-config-catalog', { label: 'config catalog' }),
     pnpmScript('persistence-catalog', 'verify-persistence-catalog', { label: 'persistence catalog' }),
     pnpmScript('doc-graphs', 'verify-doc-graphs', { label: 'doc graphs' }),
     pnpmScript('markdown-wrap', 'verify-md-wrap', { label: 'markdown wrap' }),