Phase 4.7: Cross-platform settings gate

[danielmrdev]

Parent

Part of #25 — Phase 4: Settings and appearance.

What to build

Close Phase 4 with automated and manual evidence that Settings, Preferences persistence, and font delivery work consistently on Linux, macOS, and Windows, without claiming unavailable platform checks as verified.

Acceptance criteria

• Locked formatting, all-target builds, warnings-denied Clippy, all domain tests, delivery tests, and smoke coverage pass on Linux, macOS, and Windows CI.
• A manual verification record covers OS appearance changes under System Theme, OS-configured System monospace resolution, Typeface download and offline retry, cache cleanup recovery, visual relayout, keyboard focus, sidebar accessibility, and save-failure feedback.
• Every Linux, macOS, and Windows manual cell is marked only after direct execution; unavailable checks remain explicitly unverified.
• Phase 4 remains free of non-Appearance categories, custom Themes, system font pickers, global OS font installation, unpinned downloads, network-dependent writing, and release packaging.

Blocked by

• Phase 4.4: Bundled interface typeface #30 — Phase 4.4: Bundled interface typeface.
• Phase 4.6: Settings modal and Appearance UI #32 — Phase 4.6: Settings modal and Appearance UI.

[danielmrdev]

Phase 4.7 gate is complete and merged via #36.

Evidence:

• Automated gate passes on Linux (this environment), macOS, and Windows CI: formatting, locked all-target builds, warnings-denied Clippy, full test suite (domain + delivery + smoke), and the reference-workload step. PR Phase 4.6: Settings modal and Appearance UI (+ Phase 4.7 gate) #36 runs 31157085474 and 31157457352 all green on ubuntu-latest / macos-latest / windows-latest; gitleaks clean.
• Manual verification record: docs/phase-4-cross-platform-verification.md covers OS appearance under System Theme, OS-configured System monospace resolution, Typeface download and offline retry, cache cleanup recovery, visual relayout, keyboard focus, sidebar accessibility, and save-failure feedback. All Linux/macOS/Windows cells remain ☐ (unverified) until executed directly on that platform; unavailable checks (e.g. macOS/Windows live OS appearance) are explicitly marked unverified.
• Scope guard: Phase 4 adds no non-Appearance categories, custom Themes, system font pickers, global OS font installation, unpinned downloads, network-dependent writing, or release packaging (audited in the gate).