feat(agent): make coordination routes opt-in and address review

Gate inspect, stage and submit behind the synced agentCoordinationEnabled
setting (default OFF, App Settings > Cross-session features, zh-CN
strings). While off, all three routes answer 403 FORBIDDEN naming the
setting, checked before session lookup; the CLI verbs print it verbatim.

Remember the attributed Codex rollout per session and re-verify only its
head on later calls, rescanning only date directories not older than it
for a /new conflict. The first walk reads 1 KiB prefixes first, so a
store of 2,100+ unrelated rollouts still attributes.

Answer unexpected inspection errors with 422 OPERATION_FAILED and log
the session id and error code only.

Read the guarded composer glyph and footer from the CLI registry: codex
workDetect.promptGlyph and a new workDetect.composerFooterLine
capability, compiled through compileVersionRegex. Codex footer effort
words are one shared list with modelDetect.screenLine.

Fix the wiki API reference link, frame the versioning policy entry as a
case of the experimental rule, join the CLAUDE.md Agent CLI paragraph,
and update the changeset, skill reference and architecture notes.

docs/cli-registry.md

@@ -47,9 +47,10 @@ interface CliEntry {
   env: CliEnv; // exports, tmux setenv keys, the env-override allowlist
   capabilities: CliCapabilities; // what every call site reads instead of the id
   //   .workDetect?: { promptGlyph, workingLine, watchingLine?, watchingLines?, awaitingLine?,
-  //                   blockedLine?, blockedLines? }
+  //                   blockedLine?, blockedLines?, composerFooterLine? }
   //   (how this CLI's pane shows work, work it started in the background, a turn
-  //   that ended waiting for workers it will resume from, and a dialog it is blocked on)
+  //   that ended waiting for workers it will resume from, a dialog it is blocked on,
+  //   and the rows under its idle composer that guarded input relies on)
   //   .modelDetect?: { screenLine, screenLines? }
   //   (where this CLI's own chrome names the model it runs: SessionState.displayModel)
   //   .launchDefaults?: { [launchParam]: settingsKey }
@@ -63,7 +64,7 @@ interface CliEntry {
 
 ### Regexes that come from config
 
-Six capability fields carry a regular expression an override file can set: `discovery.version.regex`, `capabilities.workDetect.workingLine`, `capabilities.workDetect.watchingLine`, `capabilities.workDetect.awaitingLine`, `capabilities.workDetect.blockedLine` and `capabilities.modelDetect.screenLine`. All six go through `compileVersionRegex()`, which caps the source at 200 characters, refuses the nested-quantifier shapes that cause catastrophic backtracking, and returns `null` rather than throwing so every caller degrades instead of crashing.
+Seven capability fields carry a regular expression an override file can set: `discovery.version.regex`, `capabilities.workDetect.workingLine`, `capabilities.workDetect.watchingLine`, `capabilities.workDetect.awaitingLine`, `capabilities.workDetect.blockedLine`, `capabilities.workDetect.composerFooterLine` and `capabilities.modelDetect.screenLine`. All seven go through `compileVersionRegex()`, which caps the source at 200 characters, refuses the nested-quantifier shapes that cause catastrophic backtracking, and returns `null` rather than throwing so every caller degrades instead of crashing.
 
 `workingLine` is the one that matters most, because it is compiled once per session and then run against every accumulated PTY chunk and every pane capture. A nested quantifier there is a ReDoS against the event loop for the whole server, not just that session. The guard therefore runs in two places, and neither is redundant: `schema.ts` rejects the entry at LOAD time so a bad pattern never reaches a session, and `_workingLinePattern()` in `session.ts` compiles through the same helper so the runtime cannot end up with a pattern the schema would have refused.
 
@@ -124,6 +125,18 @@ below, open PERMISSION items, which a watching label never acknowledges), so a f
 costs a wrong badge and cannot silence an alert. Before giving a CLI idle signals and a
 pattern, make sure its row is one the agent cannot write.
 
+### The idle composer guarded input reads (`composerFooterLine`)
+
+The experimental guarded `stage`/`submit` routes (`src/agent-staging.ts`, opt-in through
+`agentCoordinationEnabled`) type into a composer only after proving, from a fresh capture,
+that the newest `promptGlyph` row is the CLI's own composer at rest, with the caret at the
+exact end of its text. `composerFooterLine` is the second half of that proof: every
+non-blank row below the composer (at most three) must match it, one row at a time. A CLI
+that declares none never takes guarded input; only codex declares one, built from the same
+effort-word list as its `modelDetect.screenLine` (`CODEX_EFFORT_WORDS` in `stock.ts`), so a
+codex footer change is a one-place edit. Like `blockedLine`, the rows it sees are near the
+foot of the screen, so a pattern must anchor on chrome only that CLI draws there.
+
 ### Dialogs a CLI blocks on (`blockedLine`)
 
 `blockedLine` is the screen-read source of the `blocked` state for a CLI with no hook to