F02: P0: Linux capture/window matrix

Go implementation tracking epic

Selected stack: Go + Wails v2 + React/TypeScript + SQLite. Implementation starts on the next machine. Each child below is a separate PR; do not implement this epic in one PR.

Child tasks

• F02a: Wayland capture feasibility evidence
  • Merged prerequisites: F01a.
  • Acceptance: Document KDE/GNOME versions; user-approved portal capture of a test window, deny/revoke/source-close behavior; record unsupported cases without claiming game compatibility.
• F02b: X11 and companion-window feasibility
  • Merged prerequisites: F01a.
  • Acceptance: Record X11 capture, focus, scale and ordinary-window behavior; document fullscreen/shortcut/overlay limitations. Actual game checks need separate authorization.

Workflow

See TASKS.md, ROADMAP.md, and CONTRIBUTING.md. Aim for 100-400 handwritten changed lines per PR; split above 600 unless inseparable. Merge prerequisites before dependents. Update task evidence and this checklist after each completed PR. Close this epic only when every child passes; optional work can remain deferred.

All tasks are not started. Live game access and publication/merge actions follow the user's explicit authorization. The planning handoff does not claim runtime validation.

F02a environment preflight - 2026-09-10

F01c merged as PR #17. This machine is Fedora 44 x86_64 running dwm/X11. gnome-shell, plasma-workspace, xdg-desktop-portal-gnome and xdg-desktop-portal-kde are not installed. Installed portal packages are xdg-desktop-portal-1.22.1-1.fc44 and xdg-desktop-portal-gtk-1.15.3-3.fc44; the GTK backend's declared interfaces do not include ScreenCast.

Manual gate: provide KDE and GNOME Wayland test sessions and verify the user-selected test-window portal flow, denial, revocation and source-window closure. Record exact desktop/GPU/session versions and unsupported results; no game capture is needed for F02a. No Wayland compatibility is claimed from the existing X11 mock-window test. No F02a PR has been opened and its checklist remains pending.

Read TASKS.md, ROADMAP.md, and CONTRIBUTING.md, then review the F01a prerequisite and PR #17. Split work between F02a and F02b: test the specified Wayland or X11 window-capture scenarios in the required environments, and record versions, limitations, unsupported cases, and checklist updates as defined by each child's acceptance criteria.