[devin-ai-integration]

Summary

Adds a fully configurable "glass" look: the app window can request a translucent/blurred OS backdrop, and every major surface (sidebar, tab strip, toolbar, menus & popovers, Settings panel, editor) gets its own on/off toggle + opacity slider, with an optional tint and editor-text legibility options. Everything applies live and persists in the kv settings file; when glass is off every colour is byte-identical to today.

• New src/glass.rs holds the whole model: Surface enum with per-surface key()/default_percent() (sidebar + tab strip default to 75%, everything else opaque), Material with per-OS options()/default_for_os() (macOS → Blur; Windows → Acrylic/Mica/Mica Alt; Linux → "Compositor" = Transparent, or Blurred on KDE), the Glass global built from_settings, and the alpha/tint helpers (glass::bg, root_bg, blend/mix_u32, text_alpha/text_contrast). Glass defaults ON where the OS can blur, OFF on GNOME.
• Window material: WindowOptions.window_background is set at open and apply_window calls window.set_background_appearance() on every settings save — Opaque when disabled, so off = exactly today's look.
• Render sites swap their flat .bg(pal.*) for glass::bg(pal.*, Surface::X, cx) across app.rs, sidebar.rs, tabs_ui.rs, main_view.rs, spaces_ui.rs, files_menu.rs, links_ui.rs, find_ui.rs, search_ui.rs, update_ui.rs, tour.rs; popover-based menus are retinted via theme.popover in glass::apply, re-applied after apply_theme's crossfade (which lerps only the Palette global) and after theme::apply inside appearance_changed. No Palette fields added, so theme::lerp is untouched; glass::bg reads the render-pass palette, so the crossfade stays live with glass on.
• Settings > Appearance > Glass: master toggle, Material pill (only OS-valid options, with a compositor hint on Linux / GNOME warning), one Intensity slider that scales every enabled surface, and a presence()-animated Advanced/Avançado disclosure with the per-surface toggles+sliders, Theme-colour/Custom tint (ColorPicker + strength slider) and text options. New strings in en + pt-BR; settings keys appended in store.rs with glass_ prefix, missing keys → defaults.
• Editor text: text opacity slider plus a high-contrast toggle. GPUI 0.3.4 has no text shadow primitive, so legibility is implemented as a colour nudge — mix_u32 blends each run colour 40% toward pal.fg before applying text_alpha; dim_runs' fade target is glassed too so focus-mode dimming stays consistent.

Tests: glass_defaults_and_roundtrip in store.rs plus 5 tests in glass.rs covering off-is-opaque-identical, per-surface opacity, intensity scaling, tint blend and text alpha/contrast.

Not done / known limits: no text shadow (GPUI lacks it) — replaced by the contrast-nudge toggle as agreed; macOS Blurred is a light frost (NSVisualEffectMaterial::Selection), so backdrop bleed-through is subtle — the per-surface translucency does the visible work; GNOME has no compositor blur (warning shown, glass defaults off there).

Screenshots

Glass off — exactly today's look

Defaults, light theme — sidebar + tab strip 75%, rest opaque

Defaults, dark theme

Custom tint (pink, 70% strength) + sidebar/tabs 60% + editor 30%, dark

Settings panel at ~12% — note text bleeds through

Context menu at ~17% — note text visible through menu

Settings UI — minimal Glass section

Advanced disclosure — per-surface toggles, tint and text options

Editor surface at 37%

Link to Devin session: https://app.devin.ai/sessions/6b72af84455e479ba9fc810aa53400fb
Open in Devin Desktop: https://app.devin.ai/desktop/session/6b72af84455e479ba9fc810aa53400fb?variant=devin
Requested by: @horizzon3507

[devin-ai-integration]

I'll fix CI failures and address comments from users with write access. I'll skip comments containing "(aside)".

• Disable automatic comment, CI, and merge conflict monitoring