feat(cli): add CRUD helper, resource definitions, and help command

Resource-first CLI: `nc groups list`, `nc wirings get <id>`, etc.
Seven resources defined (groups, messaging-groups, wirings, users,
roles, members, sessions) with full column documentation that serves
as the single source of truth for help output and arg validation.

- CRUD helper auto-registers list/get/create/update/delete from
  declarative resource definitions with generic SQL
- Custom operations for composite-PK resources (roles grant/revoke,
  members add/remove)
- Access model: open (reads) / approval (writes) / hidden
- `nc help` lists resources; `nc <resource> help` shows fields
- Positional target IDs: `nc groups get <id>`
- Removed unused priority column from wirings

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/cli/dispatch.ts

@@ -1,10 +1,10 @@
 /**
  * Transport-agnostic dispatcher. Both the socket server (host caller) and
- * — once it lands — the per-session DB poller (container caller) call
- * dispatch() with the same frame and a transport-supplied CallerContext.
+ * the per-session DB poller (container caller) call dispatch() with the
+ * same frame and a transport-supplied CallerContext.
  *
  * Approval gating for risky calls from the container is the only branch
- * that differs by caller. Host callers and `safe` commands run inline.
+ * that differs by caller. Host callers and `open` commands run inline.
  */
 import type { CallerContext, ErrorCode, RequestFrame, ResponseFrame } from './frame.js';
 import { lookup } from './registry.js';
@@ -15,13 +15,13 @@ export async function dispatch(req: RequestFrame, ctx: CallerContext): Promise<R
     return err(req.id, 'unknown-command', `no command "${req.command}"`);
   }
 
-  // Agent + risky → approval flow. Wired alongside the first risky command;
-  // until then, return a clear pending-shaped error so the contract is visible.
-  if (ctx.caller !== 'host' && cmd.riskClass !== 'safe') {
+  // Agent + approval-gated → approval flow. Wired alongside the first
+  // approval-requiring command; until then, return a clear error.
+  if (ctx.caller !== 'host' && cmd.access === 'approval') {
     return err(
       req.id,
       'approval-pending',
-      'Approval flow not yet wired. (Will be added when the first risky command lands.)',
+      'This command requires approval. (Approval flow not yet wired.)',
     );
   }