docs: fix review findings — residual ordinals, hypothetical IPC row, citation-rule amendments

Purge the residual task/phase ordinals review caught ((T2), (queue cut 1)
×3, T6, P-I, 'this cut' ×6 including battery-expansion finds in two
untouched notes and a workflow JSDoc); drop the 'externally logged as
Decision 21' parenthetical and rename the remaining bare decision-21
mentions; mark the gui-layering IPC bridge row as a hypothetical example;
restore the GATE_NOTICE doc-typecheck clause and the py-types 'measured'
provenance; say subprocess-backed in filesystem.md; add the picker note
path. Amend the citations note: merged-PR evidence anchors in Agent Notes
are sanctioned, and the candidate gate patterns gain the four shapes the
sweep missed. All nine touched pairs re-recorded.

packages/typert/generator/src/cordis-catalog.ts

@@ -772,7 +772,7 @@ const BANNER = [
 ]
 
 /** The shared GENERATED + freshness-gate + fence notice paragraph. */
-const GATE_NOTICE = 'This file is GENERATED from source (`scripts/gen-cordis-catalog.ts`) and verified fresh by `pnpm run verify-cordis-catalog` (part of `doc-sync`) — do not edit it by hand. Signature blocks use a `ts cordis-catalog` fence and include the original source JSDoc immediately before each event or service method; type names in a signature link to the page that documents them.'
+const GATE_NOTICE = 'This file is GENERATED from source (`scripts/gen-cordis-catalog.ts`) and verified fresh by `pnpm run verify-cordis-catalog` (part of `doc-sync`) — do not edit it by hand. Signature blocks use a `ts cordis-catalog` fence and include the original source JSDoc immediately before each event or service method. doc-typecheck skips these bare declaration fragments; type names in a signature link to the page that documents them.'
 
 /**
  * Render one page's generated `cordis-surface` region: the services mapped to