Fix lsof path resolution and support server_port fallback

[athal7]

Dynamically resolves the lsof path on linux and supports fallback to preferredPort when lsof checks cannot find the running opencode server.

Fixes #117

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PR created automatically by Jules for task 3601355634390134876 started by @athal7

Summary by CodeRabbit

• Bug Fixes

  • Improved server discovery when port information is unavailable.
  • Added support for detecting running servers across common system configurations.
  • Configured preferred ports are now checked reliably during server discovery.

• Tests

  • Added coverage for discovering a server through its configured preferred port.

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[coderabbitai]

📝 Walkthrough

Walkthrough

Port discovery now resolves lsof from multiple absolute locations. Server discovery also checks the configured preferred port when port detection returns no matching port, with a corresponding unit test.

Changes

Port discovery resilience

Layer / File(s)	Summary
Resolve lsof executable service/actions.js	getOpencodePorts probes multiple absolute lsof locations and uses the first existing executable.
Check preferred port fallback service/actions.js, test/unit/actions.test.js	discoverOpencodeServer appends a configured preferred port when absent from detected ports, and tests discovery when no ports are detected.

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

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly matches the main change: lsof path resolution and server port fallback.
Linked Issues check	✅ Passed	The changes address #117 by resolving lsof from common locations and falling back to the configured preferred server port.
Out of Scope Changes check	✅ Passed	The diff stays focused on lsof discovery logic and its test coverage, with no obvious unrelated additions.
Docstring Coverage	✅ Passed	Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%.

✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch lsof-path-and-port-fallback-fixes-3601355634390134876

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[coderabbitai]

Actionable comments posted: 1

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@service/actions.js`:
- Around line 196-202: Update the lsof candidate selection loop to validate each
path with executable permissions, using accessSync and X_OK alongside existsSync
or an equivalent executable check. Only assign and break on a runnable
candidate; otherwise continue through lsofPaths so the existing default lsof
PATH fallback remains available.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

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ℹ️ Review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Pro Plus

Run ID: c8b5f5ec-fb38-429b-8477-5bf721b6020f

📥 Commits

Reviewing files that changed from the base of the PR and between 091b6e1 and d3d4eda.

📒 Files selected for processing (2)

• service/actions.js
• test/unit/actions.test.js

[coderabbitai]

🩺 Stability & Availability | 🟠 Major | ⚡ Quick win

Check that the selected lsof path is executable.
existsSync() can pick a directory or non-executable file, and execSync() will then fail without trying the remaining candidates or the PATH fallback. Use accessSync(path, X_OK) or keep iterating until one candidate can actually run.

🤖 Prompt for AI Agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

In `@service/actions.js` around lines 196 - 202, Update the lsof candidate
selection loop to validate each path with executable permissions, using
accessSync and X_OK alongside existsSync or an equivalent executable check. Only
assign and break on a runnable candidate; otherwise continue through lsofPaths
so the existing default lsof PATH fallback remains available.

[athal7]

@jules can you address the outstanding review comment from CodeRabbit above — the executable-check issue at service/actions.js:202 (use accessSync with X_OK instead of existsSync)?