fix(gfn): implement serverInfo region fallback

[zortos293]

This PR implements a fallback mechanism for getActiveSessions to prevent failures when the primary CloudMatch region endpoint is unreachable.

• Refactored getActiveSessions in src/main/gfn/cloudmatch.ts to query v2/serverInfo for fallback region URLs (local-region, gfn-regions) if the primary fetch fails.
• Added extractServerInfoRegionBases to parse and prioritize local region metadata from serverInfo response.
• Added discoverActiveSessionFallbackBases and fetchActiveSessionsFromBase to manage the retry logic and error handling.
• Updated getActiveSessions to include the stable deviceId in request headers.
• Added tests in src/main/gfn/cloudmatch.test.ts for region metadata extraction and the fallback fetch flow.

[coderabbitai]

Important

Review skipped

Auto reviews are disabled on base/target branches other than the default branch.

Please check the settings in the CodeRabbit UI or the .coderabbit.yaml file in this repository. To trigger a single review, invoke the @coderabbitai review command.

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro Plus

Run ID: 8065b610-85fa-413b-82c6-fd9bc439da18

You can disable this status message by setting the reviews.review_status to false in the CodeRabbit configuration file.

Use the checkbox below for a quick retry:

• 🔍 Trigger review

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch capy/fix-gfn-session-fallback

---

_{Comment @coderabbitai help to get the list of available commands.}

[chatgpt-codex-connector]

💡 Codex Review

Here are some automated review suggestions for this pull request.

Reviewed commit: 0b5960fea6

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review".

If Codex has suggestions, it will comment; otherwise it will react with 👍.

Codex can also answer questions or update the PR. Try commenting "@codex address that feedback".

[chatgpt-codex-connector]

Fall back after failed session responses

When the primary /v2/session request gets a non-OK response or CloudMatch API error, fetchActiveSessionsFromBase() returns [] rather than null. Since arrays are truthy, this branch returns immediately and never calls serverInfo, so the new region fallback only runs for thrown network errors; in provider/alliance cases where the generic base responds with 4xx/5xx but the local region has the active session, resume and force-new still see no sessions.

Useful? React with 👍 / 👎.