Prompt to create support bundle before Reload Window on SSH failure

Split out from coder/vscode-coder#955 point (4).

## Summary

Detect Remote-SSH failure conditions before users click VS Code's native "Reload Window" prompt, then offer to create a Coder support bundle while volatile state is still available.

## Proposed scope

* Watch the actual Remote-SSH extension log for known failure markers:
* `permanent error`
* `will give up now`
* `Unknown reconnection token`
* `socketFactory.connect() failed or timed out`
* `Time limit reached`
* `UnparsableOutput`
* Treat long process-loss/no-recovery windows as a failure signal without firing during normal reconnect cycles.
* Show a notification:
* `Coder: remote session failed and won't auto-reconnect. Capture diagnostics now?`
* Actions: `Create support bundle`, `Dismiss`
* Running `Create support bundle` should invoke the existing `coder.supportBundle` command.
* Avoid duplicate notifications in a single failing session.

## Notes

This is intentionally separate from coder/vscode-coder#955's support bundle collection changes because the current `SshProcessMonitor` discovers ports/PIDs/proxy-log paths but does not tail or classify log contents. This should be implemented as a lifecycle-safe watcher/detector rather than added opportunistically to bundle collection.

Generated by Coder Agents.

先閱讀現有的 SshProcessMonitor 和 coder.supportBundle 命令，然後檢查 VS Code 擴充功能如何觀察 Remote-SSH 狀態並記錄日誌。為列出的失敗標記和程序長時間遺失定義一個生命週期安全的偵測器，避免將正常重新連線視為故障，並避免重複警示。完成標準是通知提供 Create support bundle 和 Dismiss，且該動作呼叫 coder.supportBundle。

由索引模型根據 Issue 內容生成。