Unify transactional presentation across managed surfaces

[conxlgtm]

Summary

• Add ManagedSurfaceIdentity, one managed redraw event, and root/filtered presentation feedback for windows, popups, and subsurfaces.
• Give PopupSurface and Subsurface the same direct/prepared show and redraw contract as Window, with SurfaceFrameMetadata and SoftwarePresentationOutcome.
• Share SHM reservation, metadata, callback, feedback, commit, and cleanup machinery while retaining role-specific lifecycle reducers.
• Make popup preparation latest-wins and replace subsurface boolean redraw state with SubsurfaceModel.
• Make synchronized child-then-parent commit one point-of-no-return transaction and add live/public smoke coverage.

Transaction guarantees

• Unsupported metadata is rejected before draw, new-pool allocation, or presentation requests.
• Stale prepared work returns .superseded; close races return .closed.
• Cancellation and draw/preparation errors release reservations and preserve eligible redraw work.
• Synchronized submissions commit child then parent exactly once; rejected and desynchronized paths do not commit the parent.

Validation

• Root suite: 2,010 tests passed.
• Focused TSan: 27 pure tests + 3 live subsurface tests passed with no sanitizer report.
• wck ci cheap, wck ci required, API baseline verification, DocC verification, documentation verification, identity verification, formatting, lint, and git diff --check: passed.
• Headless public integration and request-path suites: passed.
• GitHub PR checks cheap, headless-request-path, required-product, and aggregate required: passed.
• Framework-host external package compiled and its live Weston path created/drew all three roles.
• ManagedSurfacePresentationSmoke: passed on Weston 15 with all feedback/redraw routes and cleanup; passed on KDE/KWin 6.6.6 for all initial presentations and cleanup using bounded compositor flags.

Review

The exact candidate tree was reconstructed from a SHA-256-pinned patch and independently reviewed. Final verdict: MERGE , no merge blockers found. The review also reran 38 focused tests, 4 live subsurface transaction tests, 2 live public-integration tests, 3 focused live TSan tests, and the headless smoke.

[chatgpt-codex-connector]

💡 Codex Review

Here are some automated review suggestions for this pull request.

Reviewed commit: cafdbc0e24

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".

[conxlgtm]

@codex review

[chatgpt-codex-connector]

Codex Review: Didn't find any major issues. 🎉

Reviewed commit: bd6ae41e24

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".