refactor(self-mod): drop request_rebuild — approvals now bundle rebuild+restart

install_packages and add_mcp_server already did the right thing on approve
(install auto-rebuilt+killed, add_mcp_server just killed), so request_rebuild
was redundant plumbing agents sometimes called after an install — wasting an
admin approval round-trip. Delete it end-to-end:

- container/agent-runner/src/mcp-tools/self-mod.ts: remove requestRebuild
  tool + registration; update install_packages description.
- src/modules/self-mod/{request,apply,index}.ts: drop handleRequestRebuild
  + applyRequestRebuild + registrations; rewrite the rebuild-failed notify
  to point admins at retrying install_packages instead.
- src/modules/{approvals,self-mod}/{agent,project}.md and skill/self-
  customize/SKILL.md: scrub agent-facing references; clarify that
  add_mcp_server needs no rebuild (bun runs TS directly).
- docs/{module-contract,architecture-diagram,checklist,db-central,shared-
  source,v1-vs-v2/*}.md, CLAUDE.md, pending-approvals migration comment,
  approvals/index.ts docstring, REFACTOR.md: trailing references.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/db/migrations/module-approvals-pending-approvals.ts

@@ -3,8 +3,8 @@ import type { Migration } from './index.js';
 /**
  * `pending_approvals` table — host-side records for any approval-requiring
  * request. Used by:
- *   - install_packages / request_rebuild / add_mcp_server  (session-bound,
- *     `session_id` set, status stays at default 'pending' until handled)
+ *   - install_packages / add_mcp_server  (session-bound, `session_id` set,
+ *     status stays at default 'pending' until handled)
  *   - OneCLI credential approvals from the SDK `configureManualApproval`
  *     callback (session_id may be null, action='onecli_credential').
  *