[FEATURE]: Add Kimi WebBridge support (like Claude Code / Cursor / Codex)

Describe the enhancement

Support Kimi WebBridge as a browser control backend for opencode, parity with Claude Code / Cursor / Codex / Hermes / OpenClaw.

Kimi WebBridge is official: https://www.kimi.ai/products/kimi-webbridge

• Works via local service + browser extension (Chrome DevTools Protocol)
• Everything runs locally
• Install command on Windows: irm https://cdn.kimi.com/webbridge/install.ps1 | iex
• Connect flow: paste Install Kimi WebBridge: irm ... | iex to Agent -> Agent connects automatically

Currently opencode is not in the supported list (only Kimi Code / Claude Code / Cursor / Codex / Hermes / OpenClaw per official UI). Pasting the command in opencode does nothing.

Proposed solution

• Detect WebBridge local service if installed
• Add bridge client similar to other agents
• Or add generic browser tool backed by WebBridge when available

Use cases

• Browse docs & extract examples
• Fill forms / web app interaction
• Screenshot / debug web pages
• Web scraping with logged-in session

Related

• #27543, #27541, #26772, #6992 (previous browser tool requests)