refactor(modules): re-tier approvals as default; extract self-mod as optional

Promotes approvals to the default tier with a public API (requestApproval +
registerApprovalHandler) that other modules consume. Self-modification
(install_packages / request_rebuild / add_mcp_server) moves into a new
optional module that registers delivery actions + matching approval handlers
via the new API.

## Approvals (default tier)

- Adds `src/modules/approvals/primitive.ts` exporting `requestApproval`,
  `registerApprovalHandler`, `notifyAgent`. Absorbs `pickApprover` /
  `pickApprovalDelivery` / `channelTypeOf` from the deleted `src/access.ts`.
- Rewrites `response-handler.ts` to dispatch to registered approval handlers
  on approve (action-keyed Map). Reject path is centralized.
- Drops the three self-mod-specific delivery-action registrations from
  `approvals/index.ts`; they belong to self-mod now.
- `onecli-approvals.ts` now imports picks from the primitive instead of
  `src/access.ts`.

## Self-mod (optional tier)

- New `src/modules/self-mod/` with request handlers (validate input + call
  requestApproval) and apply handlers (orchestration on approve).
- `apply.ts` owns updateContainerConfig + buildAgentGroupImage + killContainer
  calls. Self-mod depends on approvals (via registerApprovalHandler +
  requestApproval + notifyAgent) and on core (container-runner, container-config).
- Registers 3 delivery actions + 3 approval handlers at import time.

## Other changes

- `src/access.ts` and `src/access.test.ts` deleted. Tests split across
  `src/modules/approvals/picks.test.ts` (approver selection) and
  `src/modules/permissions/permissions.test.ts` (access + roles + DM).
- `src/modules/index.ts` barrel: approvals loads before self-mod so
  registerApprovalHandler is bound when self-mod registers at import time.

## Validation

- `pnpm run build` clean
- `pnpm test` — 137 host tests pass
- `bun test` in container/agent-runner — 17 tests pass
- Service starts; boot log shows `OneCLI approval handler started`,
  `NanoClaw running`; clean SIGTERM shutdown

Resolves the transitional tier violation flagged in PR #5 where core
imported from the permissions optional module via `src/access.ts`.

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

src/modules/approvals/index.ts

@@ -1,30 +1,29 @@
 /**
- * Approvals module — admin-gated self-modification and OneCLI credential flow.
+ * Approvals module — admin approval primitive + response plumbing.
+ *
+ * Default-tier module. Ships with main. Other modules depend on it by
+ * importing `requestApproval` / `registerApprovalHandler` from this module.
  *
  * Registers:
- *   - Three delivery actions the container writes via self-mod MCP tools:
- *     install_packages, request_rebuild, add_mcp_server.
- *   - A response handler that claims `pending_approvals` rows (agent-initiated
- *     approvals) + OneCLI credential approvals (resolved via in-memory Promise).
+ *   - A response handler that claims pending_approvals rows and dispatches
+ *     to whatever module registered for the row's `action` string. Also
+ *     resolves in-memory OneCLI credential approvals.
  *   - An adapter-ready callback that starts the OneCLI manual-approval handler
  *     once the delivery adapter is set.
  *   - A shutdown callback that stops the OneCLI handler cleanly.
+ *
+ * Self-mod flows (install_packages, request_rebuild, add_mcp_server) moved
+ * out to `src/modules/self-mod/` in PR #7 — they now register delivery
+ * actions + approval handlers via this module's public API.
  */
-import { registerDeliveryAction, onDeliveryAdapterReady } from '../../delivery.js';
+import { onDeliveryAdapterReady } from '../../delivery.js';
 import { registerResponseHandler, onShutdown } from '../../response-registry.js';
-import { handleAddMcpServer, handleInstallPackages, handleRequestRebuild } from './request-approval.js';
 import { handleApprovalsResponse } from './response-handler.js';
 import { startOneCLIApprovalHandler, stopOneCLIApprovalHandler } from './onecli-approvals.js';
 
-registerDeliveryAction('install_packages', async (content, session) => {
-  await handleInstallPackages(content, session);
-});
-registerDeliveryAction('request_rebuild', async (content, session) => {
-  await handleRequestRebuild(content, session);
-});
-registerDeliveryAction('add_mcp_server', async (content, session) => {
-  await handleAddMcpServer(content, session);
-});
+// Public API re-exports so consumers import from the module root.
+export { requestApproval, registerApprovalHandler, notifyAgent } from './primitive.js';
+export type { ApprovalHandler, ApprovalHandlerContext, RequestApprovalOptions } from './primitive.js';
 
 registerResponseHandler(handleApprovalsResponse);