ci: add ps2dev latest migration probe workflow

[NathanNeurotic]

Motivation

• Preserve the existing known-good CI path while adding a conservative diagnostic probe for ps2dev/ps2dev:latest to surface the first incompatibility without changing source or production jobs.
• Run the same build under both the legacy container and the new Alpine-based container so differences in host tools, SDK layout, or toolchain behavior are visible.
• Capture a compact but useful fingerprint and PS2SDK snapshot so the first failure cause is explainable and triageable.
• Keep both runs independent by setting fail-fast: false so failures from the new probe do not hide the working build.

Description

• Add a new workflow file .github/workflows/ci-ps2dev-migration-probe.yml that defines a build-probe job running a matrix over two containers: ps2max/dev:v20250725-2 and ps2dev/ps2dev:latest.
• The job includes a guarded Alpine install step that runs only when apk is available and installs the requested host packages for diagnostics.
• The workflow captures an environment/toolchain fingerprint into env-fingerprint.log (including /etc/os-release, uname -a, env, PS2DEV/PS2SDK/GSKIT, PATH, which checks, cross-compiler --version, Defs.make preview, and selected Makefile vars) and a PS2SDK file snapshot ps2sdk-snapshot.log.
• The workflow runs the exact production build command make --trace clean release and tees the output into build.log, then always uploads env-fingerprint.log, ps2sdk-snapshot.log, and build.log as artifacts named per-matrix (diagnostics-<label>).

Testing

• Verified the new workflow file exists and its contents using repository file listing and file-content inspection commands (rg, sed, nl), which confirmed the expected steps and placement (succeeded).
• Generated and reviewed the patch/diff to confirm only the new diagnostic workflow was added and no production workflows or source files were modified (succeeded).
• Created the workflow file in the branch as the PR change; no GitHub Actions run was executed in this environment so the workflow execution and artifact uploads are unverified here (CI run required to collect build.log and classify the first failure).

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Codex Task

[gemini-code-assist]

Note

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