docs: repair rewritten rationale and stale claims from the ACP reduction

The automation-only rewrite edited many implemented Agent Notes; several
edits replaced still-live or historical rationale instead of reframing:

- llm-model-catalog: restore the prompt/request consistency section and
  selection-ownership alternatives — installAgentLlmTarget and the TUI
  /model selector still ship that design; only the ACP wire is gone.
- plan-specific-collaboration-state, acp-multi-session, todo-write,
  ask-user-question: link the superseding automation-only note instead
  of silently rewriting the original decision or motivation; drop a
  paragraph duplicating the Web-provider facts stated two paragraphs up.
- sandbox: stop claiming unit coverage for turn-enclosed config writes
  (that mechanism left with the bridge) and retitle the commit-boundary
  paragraph accordingly.
- Fix the missing blank line before '## Consequences' in the
  plugin-command-registration pair, the JSON-RPC/Web render-intent
  consumer misattribution (the second consumer is the host/client
  runtime), stale bash_output/bash_kill names, and 'optional goals' in
  architecture.md.
- examples/acp-agent/README.md: point at the package contract instead
  of restating it; packages/ui/permission and plan-mode READMEs record
  the consumer-less preset service and the exit_plan_mode coverage gap
  under Known Limitations.
- 2026-06-19-acp-snapshot-tests: the new note defers the corpus
  migration rather than committing to it; say so.

Re-record the touched bilingual pairs.

packages/plan/plan-mode/README.md

@@ -86,3 +86,4 @@ Mode transitions do not change the tool catalog; plan arguments and review resul
 - Plan mode guides rather than enforces; deployments needing a hard boundary must combine independent sandbox and approval controls.
 - A pending selection made while idle is lost if the process exits before the next boundary, so the UI must reapply it.
 - Forked agents inherit logged plan state, while newly spawned agents begin inactive; there is no creation-time plan option.
+- The `exit_plan_mode` review arc (submit → human review → approved flip or rejected feedback) is covered by package tests only; its assembled-application snapshot left with the retired ACP UI scenarios ([automation-only ACP](../../../.agents/notes/implemented/simplification/2026-07-23-acp-automation-only-protocol.md)) and the TUI keyless scenarios exercise only `/plan` entry and `/plan off` exit.