refactor(skills): collapse setup skill to one instruction — run bash nanoclaw.sh

Deletes the Claude-orchestrated /setup and /new-setup flows. The scripted installer (bash nanoclaw.sh → setup:auto) now handles bootstrap, container, OneCLI, auth, service, first agent, and optional channel wiring end-to-end with inline Claude-assisted recovery on failure. Keeps /setup as a one-line redirect so the trigger still resolves. Drops the opt-out diagnostics files that belonged to the old flow and updates cross-refs in add-wechat, migrate-nanoclaw, and update-nanoclaw.

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

.claude/skills/add-wechat/SKILL.md

@@ -167,4 +167,4 @@ Otherwise, restart the service to pick up the new channel and wiring.
 - **supports-threads**: no (WeChat has no reply threads)
 - **typical-use**: Long-poll — the adapter holds a persistent connection to Tencent's iLink API and receives messages in real time. No webhook URL needed.
 - **default-isolation**: `shared` session mode per messaging group (DM or room). Use `strict` sender policy if you want only specific users to reach the agent; `public` opens it to anyone who messages the bot.
-- **post-install-wiring**: Use the `wire-dm.ts` helper (see the "Wire your first DM" section above) if running this skill standalone. If running inside `/new-setup`, `init-first-agent.ts` handles wiring — just pass the `platform-id` and `admin-user-id` captured above.
+- **post-install-wiring**: Use the `wire-dm.ts` helper (see the "Wire your first DM" section above) if running this skill standalone. If running as part of `bash nanoclaw.sh`, `init-first-agent.ts` handles wiring — just pass the `platform-id` and `admin-user-id` captured above.