Gate JSDoc completeness on every package export

New doc-sync gate verify-export-jsdoc walks every module-level exported
name under packages/*/*/src and requires description prose everywhere,
plus @param per parameter and @returns on non-void annotated returns for
function-like exports, public class methods, properties, and accessors.
The parsing + check helpers move out of gen-cordis-catalog.ts into a
shared scripts/jsdoc.ts so 'documented' means one thing on both gated
surfaces.

Deliberate exemptions (documented in the RFC): heritage-declared class
members (the seam declaration is the doc's one home — the one checker
query in an otherwise pure-AST walk), cordis plugin-protocol slots
(name/inject/reusable/Config/apply, top-level and static), constructors,
overload implementations, declare-module augmentation bodies, and
re-export statements (checked at the defining module).

The 203 under-documented exports the gate found at adoption are filled
in this change, so the gate lands green; generated catalogs/graphs are
regenerated for the shifted line pointers.

RFC: docs/rfc/implemented/process/2026-07-06-export-surface-jsdoc-gate.md

docs/rfc/INDEX.md

@@ -142,6 +142,7 @@ Generated by `pnpm run gen-rfc-index` from the RFC tree — never edit by hand;
 | [Generate the RFC index tables](implemented/process/2026-07-04-generate-rfc-index-tables.md) | 2026-07-04 |
 | [Generated persistence log event catalog](implemented/process/2026-07-04-persistence-log-catalog.md) | 2026-07-04 |
 | [One gated in-file format for RFCs](implemented/process/2026-07-05-uniform-rfc-format.md) | 2026-07-05 |
+| [Export-surface JSDoc gate](implemented/process/2026-07-06-export-surface-jsdoc-gate.md) | 2026-07-06 |
 
 ### Testing