feat: add Appearance settings and Save both

[Majkey25]

Changes

• Rename the combined manual-save button to Save both, with translations.
• Add Settings → Appearance: independent light/dark presets, System/Light/Dark mode, Material You on Android12+, custom accent/background colors with previews, fonts, text size, corner rounding, pure-black dark mode, and reset.
• Persist appearance separately from scan rendering and retain existing defaults until changed.
• Keep custom text/buttons readable on actual dialog surfaces, synchronize late committed settings, and restore sliders after failed saves.
• Defer PDF preset-list initialization to prevent a cold settings crash.
• Prepare1.9.0/code46. Public source remains fully unlocked with no Ads or Billing.

Verification

• Palette, invalid-input, persistence, and private access-mode preservation checks passed.
• Independent Codex review found three issues; all addressed. Claude review was unavailable due to weekly limit.
• Final signed public gate passed:617 JVM tests,0 failures/skips, lint0 errors21 warnings1 hint, APK/AAB package/certificate/provenance and no-Ads/no-Billing policy checks.
• CI37645292626 passed for ae3a7da.
• Huawei Android10 isolated QA uses actual production composables + SettingsStore. Verified cold Settings startup, separate Ocean-light/Forest-dark themes, Dark mode, invalid/valid custom colors, font/text persistence after restart, corners, pure-black dark mode, reset, both rejected sliders, and late settings synchronization before a font change.
• Save both label and Both callback verified; isolated label test does not assert new MediaStore writes.
• Material You remains SDK12+ guarded; real wallpaper-color execution was not tested on the Android10 device.
• QA app removed; production apps/data and global settings unchanged.

[chatgpt-codex-connector]

Codex Review Summary

This comment shows the latest Codex review activity on this pull request.

Review	Status	Commit	Review trigger
📝 Code Review	✅ Completed 2026-10-07T16:04:41.338415Z	ae3a7da	Draft marked ready
🔒 Security Review	✅ Completed 2026-10-07T16:05:21.446758Z	ae3a7da	Draft marked ready

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