Port /impeccable generate to the engine crates

The Node-era server, CLI, hook, and pin halves of the generate command move
into the Rust workspace, with the protocol unchanged:

- crates/live: POST /agent-target is held open on a channel plus a timer
  thread (the manual-apply deferred pattern), releasing its turnstile
  ticket before it parks like /poll; /agent-target-result resolves it;
  /agent-target-claim is the roll call with its renewable lease. SSE
  connections carry the overlay's clientId: a late overlay is replayed
  every pending target, and a disconnect retires that overlay's report,
  releases its lease, and re-judges each roll call. Shutdown drains held
  requests with server_stopping.
- crates/live/src/live_generate.rs: the live-generate verb (the router
  already forwards every live* verb), same flags, verdicts, and
  _instructions, spelled with the engine's self command.
- crates/hook: every entry stands down on live preview markers
  (skipped: live-preview), checking the proposed content and the file on
  disk for hook-before-edit.
- crates/context: pin accepts generate; the crate's command-metadata.json
  copy carries its entry.

Tests: crates/cli/tests/agent_target.rs (six HTTP cases with an SSE reader),
tests/live-agent-target.test.mjs rewritten to drive the binary (28 cases,
registered in the live suite), hook stand-down cases, oracle goldens for
live-generate plus the re-recorded pin list goldens, the e2e prompt
assertion waiting for the journaled event, and the contract documented in
docs/CLI-CONTRACT.md.

AI-assisted: implemented and tested with Claude Code under maintainer
direction.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

skill/reference/generate.md

@@ -8,7 +8,7 @@ Three prohibitions cover the known ways this command goes wrong. Each names the
 
 - The poll shows no generate event yet, and writing variants straight into source feels faster. **Never hand-write a variants wrapper or invent a session id.** Only the browser mints session ids (8 hex characters, at Go), and the server refuses events for any other id; a missing event is fixed in Step 2 or Step 3, never with a direct source edit.
 - Handing the user a link to click feels polite. **Open the page yourself** (Step 2); a pasted link usually means no page ever connects.
-- The design hook may flag the preview scaffolding you just published. **Do not act on hook findings while live markers are in the file**, and do not restyle variants to appease them; `live-complete.mjs` verifies the file once the accepted variant is permanent. Current hooks stand down on the markers themselves; older installed hooks may still nag.
+- The design hook may flag the preview scaffolding you just published. **Do not act on hook findings while live markers are in the file**, and do not restyle variants to appease them; `impeccable live-complete` verifies the file once the accepted variant is permanent. Current hooks stand down on the markers themselves; older installed hooks may still nag.
 
 ## Step 1: Parse the request
 
@@ -38,7 +38,7 @@ Done when you hold an action from the vocabulary, a count from 1 to 8, and the e
 Run the boot exactly as [live.md](live.md)'s Start section describes:
 
 ```bash
-node {{scripts_path}}/live.mjs
+{{scripts_path}}/impeccable live
 ```
 
 **`config_missing` / `config_invalid`**: follow [live-setup.md](live-setup.md) first.
@@ -56,7 +56,7 @@ Done when the boot printed `"ok": true` and a page with the overlay is connected
 Derive the selector from project source, not from guesswork: an id first, then a unique class, then a landmark tag plus class. **The request names a repeated component in plural** ("the pricing cards"): target the container that holds the set, so scoped CSS restyles every instance at once. **Unsure the selector resolves uniquely**: probe with `--dry-run`; it resolves and reports without starting anything, and it works even mid-session.
 
 ```bash
-node {{scripts_path}}/live-generate.mjs --selector "section.pricing" --action bolder --count 3
+{{scripts_path}}/impeccable live-generate --selector "section.pricing" --action bolder --count 3
 ```
 
 Flags: `--selector` (required), `--action`, `--count`, `--prompt`, `--text` (keep only matches whose visible text contains a snippet), `--index` (1-based pick among matches), `--dry-run`, `--wait-for-browser <ms>`.
@@ -78,10 +78,10 @@ Then tell the user, in one line, where their variants are: *"Three [bolder] vari
 
 ## Step 5: Close the session
 
-Generate is a one-shot command; this is where it diverges from an open-ended `live` session. Once the accept (or discard) completes, wrap up without being asked: carbonize cleanup is done and `live-complete.mjs` printed `phase: "completed"` (a discard needs no cleanup), so kill your background poll and run live.md's Cleanup:
+Generate is a one-shot command; this is where it diverges from an open-ended `live` session. Once the accept (or discard) completes, wrap up without being asked: carbonize cleanup is done and `impeccable live-complete` printed `phase: "completed"` (a discard needs no cleanup), so kill your background poll and run live.md's Cleanup:
 
 ```bash
-node {{scripts_path}}/live-server.mjs stop
+{{scripts_path}}/impeccable live-server stop
 ```
 
 Stopping removes the injected live script, and that removal reloads the page one last time: the user's browser now shows the accepted design with no overlay chrome, still served by their dev server.