fix(ssh): stop killing the managed server on reconnect

[morgaesis]

What Changed

Fixes packages/ssh/src/tunnel.ts so a desktop reconnect no longer stops a healthy managed t3 serve. The remote launch script handed a connection to the server named in userdata/server-runtime.json and stopped its own managed server, but the managed server runs with that same base directory, so the runtime file usually names the managed server itself. The handoff now only happens when the runtime file's pid differs from the managed pid; a matching pid falls through to the existing reuse checks instead. Two tests run the real launch script against a throwaway home: the reconnect test fails on current main and passes with the fix, and the other confirms a separately started default server still takes over.

Why

When the desktop app reconnects to an SSH environment, the launch script could abort a healthy managed server and the provider sessions and agent turns running on it, because it mistook its own managed server for a stale default one needing a handoff. Restricting the handoff to a different pid removes that failure. #10951 contains an equivalent guard plus a separate change that stops the tunnel finalizer from stopping the remote server when the desktop closes or replaces a tunnel; this PR covers only the launch-script path and adds a test for handoff to a different server.

Checklist

• Small and focused
• Explains what changed and why
• Before/after screenshots for any UI changes (no UI changes)
• Video for animation/interaction changes (no UI changes)

[macroscopeapp]

Approvability

Verdict: Not approved

Macroscope's review found this PR not approvable — The SSH fix narrowly preserves a healthy managed server on reconnect while retaining handoff to a different default server, with focused real-process tests for both paths. Human review is required because the test file adds a file-level directive suppressing the nodeBuiltinImport static-analysis diagnostic.

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• packages/ssh/src/tunnel.test.ts

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📝 Walkthrough

Walkthrough

The remote launch script clears the default runtime port when its PID matches the managed server. Effect-based integration tests cover reuse of the managed server and handover to a separate default server.

Changes

SSH remote launch

Layer / File(s)	Summary
Managed and default server selection packages/ssh/src/tunnel.ts, packages/ssh/src/tunnel.test.ts	The launch script clears the default runtime port when its PID matches the managed server. Effect-based integration tests verify that repeated launches reuse the managed server and that a different default server causes handover. The tests use a temporary home, retry while waiting for the default server runtime file, and register process cleanup.

Priority: ⬇️ Low

Estimated code review effort: 2 (Simple) | ~10 minutes

Change: Bug fix

Suggested reviewers: juliusmarminge

Merge Risk: ⚪ Minimal · up to 86fa1

The reconnect change is mergeable after normal checks; no concrete outstanding issue is established.

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check. Docstring coverage is scoped to functions touched by this diff. Analyzed 0 functions across 2…
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Title check	✅ Passed	The title clearly and concisely describes the main SSH reconnect fix: preventing the managed server from being stopped during reconnect.
Description check	✅ Passed	The description includes complete What Changed and Why sections, explains the PID-based fix and test coverage, and completes the checklist. The UI Changes section is not needed because the PR makes no…

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Actionable comments posted: 1

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🤖 Prompt to fix review comments

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Inline comments:
In `@packages/ssh/src/tunnel.test.ts`:
- Line 372: Update the launch test around spawnSync to read any existing PID
file and record its PID in pids before asserting result.status, so the finally
cleanup can stop the server even when the assertion fails; retain the managedPid
cleanup behavior.

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Reviewing files that changed from the base of the PR and between 894d334 and 9965472.

📒 Files selected for processing (2)

• packages/ssh/src/tunnel.test.ts
• packages/ssh/src/tunnel.ts

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