Review found verify-type-equiv only scanned docs the manifest already named, so
a type-equiv block in an unmanifested doc was silently skipped — defeating the
1:1 guarantee. Scan all docs in the markdown glob scope instead, so an orphan
block in any doc is caught. Also parse `abstract class` in blockSymbol (matches
sourceDeclaration's class support).
persistence.md listed the SessionPersistence surface as create/append/load/list;
the abstract service also exposes has/delete. AGENTS.md's doc-sync command
summary omitted verify-md-links and verify-type-equiv.
Introduce a `ts type-equiv` Markdown fence: a verbatim paste of a source type
definition that `scripts/verify-type-equiv.ts` drift-checks against the source
symbol via the TypeScript parser, with provenance in a central
`scripts/type-equiv.manifest.json` kept 1:1 with the blocks. doc-typecheck
recognizes the same fence, skips compiling it (not standalone-compilable), and
excludes it from the opt-out ratio. Wired into the `doc-sync` chain.
Tianyi Cui