feat(web): add Cloudflare Quick Tunnel support for remote access (#85)

* feat(web): add Cloudflare Quick Tunnel support for remote access

Implement --try-cf-tunnel flag that creates a temporary public URL
routing to the locally running server via cloudflared.

Features:
- Auto-detect and spawn cloudflared subprocess
- Extract and display *.trycloudflare.com URL
- Proper cleanup on server shutdown
- Dynamic port handling (tunnel routes to actual listening port)
- Isolated HOME dir to avoid config conflicts
- Installation help and limitations warning

* docs: add Cloudflare tunnel feature to README

- Document --try-cf-tunnel flag in CLI examples
- Add Cloudflare Quick Tunnel to Web/PWA features

* docs: add cloudflared as prerequisite for --try-cf-tunnel

* feat(web): auto-generate password for Cloudflare tunnel

When using --try-cf-tunnel without --ui-password, automatically generate
a secure random password to protect the publicly exposed service.

Features:
- 16-character random password (easy to read, no ambiguous characters)
- Password is displayed after tunnel is established
- Warning to save the password (not shown again)
- Works in both foreground and daemon modes
- Uses same password for subsequent restarts (stored in instance file)

* fix(web): improve Cloudflare tunnel UX and fix spawn ENAMETOOLONG

- Generate and display password before tunnel starts (green colored)
- Display tunnel URL in cyan via onTunnelReady callback
- Fix ENAMETOOLONG by using env:undefined instead of copying process.env
- Pass tryCfTunnel flag from CLI to main function
- Remove duplicate tunnel URL output
- Update warning message to reflect password protection
- Change start script to use CLI wrapper for proper initialization

---------

Co-authored-by: aptdnfapt <197602950+aptdnfapt@users.noreply.github.com>

README.md

@@ -59,6 +59,7 @@ The whole project was built entirely with AI coding agents under my supervision.
 - Mobile-first UI with gestures and optimized terminal controls
 - Self-serve web updates (no CLI required)
 - Update and restart keeps previous server settings (port/password)
+- Cloudflare Quick Tunnel support for easy remote access (`--try-cf-tunnel`)
 
 ### Desktop (macOS)
 
@@ -91,6 +92,7 @@ openchamber                          # Start on port 3000
 openchamber --port 8080              # Custom port
 openchamber --daemon                 # Background mode
 openchamber --ui-password secret     # Password-protect UI
+openchamber --try-cf-tunnel          # Create a Cloudflare Quick Tunnel for remote access
 openchamber stop                     # Stop server
 openchamber update                   # Update to latest version
 ```
@@ -103,6 +105,7 @@ Download from [Releases](https://github.com/btriapitsyn/openchamber/releases).
 
 - [OpenCode CLI](https://opencode.ai) installed
 - Node.js 20+ (for web version)
+- [cloudflared](https://github.com/cloudflare/cloudflared/releases) (required for `--try-cf-tunnel`)
 
 See [CONTRIBUTING.md](./CONTRIBUTING.md) for guidelines.