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/client/ui-conversation/tests/input-matrix.spec.tsx

@@ -184,7 +184,7 @@ describe('matrix row: locked (session disabled)', () => {
     expect(shell.snapshot.phase).toBe('plain')
   })
 
-  it('running does NOT lock (queue cut 1): typing and enter-queue stay live', () => {
+  it('running does NOT lock: typing and enter-queue stay live', () => {
     const { textarea, sink } = bench({ running: true })
     expect((textarea).disabled).toBe(false)
     fireEvent.change(textarea, { target: { value: '排队' } })

packages/client/ui-conversation/tests/input-scenarios.spec.tsx

@@ -34,7 +34,7 @@ interface FakeCommand {
   input?: { hint: string }
 }
 
-/** T6 decision-table source over an in-memory directory (menu/space/enter columns for leadingInput + execute). */
+/** Decision-table source over an in-memory directory (menu/space/enter columns for leadingInput + execute). */
 function commandSource(commands: FakeCommand[], execute: (line: string) => Promise<SubmitOutcome>) {
   const resolve = (name: string): FakeCommand | undefined => commands.find(c => c.name === name)
   const leadingClaim = (desc: FakeCommand): CommandClaim => ({