Simplify remote access setup UX

[stritt]

Problem

Currently there are two separate "remote" concepts that confuse users:

1. access: 'local' | 'remote' - whether to use cloudflared tunnel for the bridge
2. deployed: boolean - whether the Cloudflare Worker (AI chat UI) is deployed

This leads to confusing states like access: 'remote' + deployed: false - the tunnel is set up but there's no UI to use it.

Current User Report

User selected remote access, deploy failed silently, ended up with:

• An orphan worker on their Cloudflare account (from wrangler secret put)
• deployed: false in config
• No working remote setup

Proposed Solution

Simplify to a single choice:

• Local: Everything on localhost, access from same machine only
• Remote: Deploy worker AND set up tunnel, access from anywhere

If they pick "remote" and deploy fails:

1. Show clear error with actionable steps
2. Fall back to local mode
3. Explain what went wrong and how to retry

Acceptance Criteria

• Single "local or remote" choice in setup wizard
• Remote = deploy + tunnel (both required)
• Clear error recovery path if deploy fails
• No orphan workers created on failure (fixed in 804c449)

[stritt]

Users have to run npm install in cloudflare-agent and then wrangler deploy in that dir to get it to work.

We need to automate this so it's simpler.