rename app layout to shell and add window frame

docs/PLAN.md

@@ -278,16 +278,17 @@ Survey notes — worth adopting later, not now: bezel's hover card (profile prev
 
 ### 6.4 The layout crate (`crates/layout`) — application shell bootstrap
 
-A new crate (D18: advanced crates are created on demand, not speculatively) that bootstraps the application layout the way zed's workspace and gpui-kit's dock do, with a deliberately smaller API (D26): a left sidebar (on by default), a right sidebar (off by default), and a center dock whose panes the user can drag and split. A panel can declare that it needs the right sidebar; activating it opens the sidebar automatically. [signed](https://git.reya.info/reya/signed)'s `crates/dock` — a gpui-component `DockArea` behind a custom skin — is the usage reference and the cautionary tale: its renderer seams, serialization placeholders, and zoom/collapse modes mark the complexity we skip. gpui-kit's dock and zed's editor dock are read as API-design references only (D15, D20). Facade feature `layout`; the crate depends on `core` and may compose `data` — at L3, decide whether `Tabs` gains optional close buttons + drag sources for pane headers or panes render their own header row. New `IconRole`s (panel-left/right toggles, split directions) land in the icons crate with the units that need them. Everything is theme-baked per §4.3 — no style parameters, no renderer/skin seam.
+A new crate (D18: advanced crates are created on demand, not speculatively) that bootstraps the application layout the way zed's workspace and gpui-kit's dock do, with a deliberately smaller API (D26): a left sidebar (on by default), a right sidebar (off by default), and a center dock whose panes the user can drag and split. A panel can declare that it needs the right sidebar; activating it opens the sidebar automatically. [signed](https://git.reya.info/reya/signed)'s `crates/dock` — a gpui-component `DockArea` behind a custom skin — is the usage reference and the cautionary tale: its renderer seams, serialization placeholders, and zoom/collapse modes mark the complexity we skip. gpui-kit's dock and zed's editor dock are read as API-design references only (D15, D20). Facade feature `layout`; the crate depends on `core` and composes `data` (`Sidebar`) — at L3, decide whether `Tabs` gains optional close buttons + drag sources for pane headers or panes render their own header row. A `window_frame` module wraps a window root in the client-side frame the OS owes — border, `Radius::overlay` corners, dialog-elevation shadow, resize bands — under `Decorations::Client` and passes through under `Server` (adapted from bezel's `window::frame` and gpui-kit's `WindowBorder`, simplified; the window must open transparent). New `IconRole`s (panel-left/right toggles, split directions) land in the icons crate with the units that need them. Everything is theme-baked per §4.3 — no style parameters, no renderer/skin seam.
 
 Units, each through the review gate:
 
 | Unit | Crate | Component | Notes |
 | --- | --- | --- | --- |
 | L1 | layout | ResizeHandle ✅ Landed (2026-11-01) | The drag divider primitive: a thin themed handle that resizes the adjacent region (sidebar edge, split seam). Pointer drag, double-click resets to the default fraction, splitter a11y role. Lives in `layout` — promotes to `core` if a second consumer appears (D16). Shipped as a delta reporter: `ResizeHandle::new(id).axis(Axis).on_resize(delta)` hands the owner the signed seam movement per event — the owner stores a pixel size and clamps, the `InputState::scroll_by` pattern — with `.on_reset()` for double-click; no geometry parameters, so it works at any edge or seam. The hairline is `border`, highlights to `ring` on hover/drag; hit slop = `dense_padding_x` (component-own decoration, D25), hairline 1 px like the input's paint hairlines; `Role::Splitter` + focus ring, arrow keys move the seam (`KEYBOARD_STEP` 32 px, input-style const). One gpui dispatch lesson locked in tests: bubble runs user mouse-down listeners before the div's own focus transfer, so a listener that stops propagation must focus explicitly first — the keyboard test caught it. Feature `resize_handle`; 6 headless tests in `crates/layout/tests/resize_handle.rs`; gallery section shows a draggable split with live width |
-| L2 | layout | AppLayout ✅ Landed (2026-11-01) | The bootstrap shell: left sidebar region (on by default) + center + right sidebar region (off by default). Sidebar toggle in each sidebar's header, drag-resize widths through `ResizeHandle`; visibility and widths live on an application-owned `LayoutState` (the `InputState` pattern: `set_left_sidebar_visible` / `set_right_sidebar_visible` / `is_*` readers). The center region hosts the `Dock`. Shipped so: the left sidebar is the data crate's `Sidebar` component (`.left_sidebar(sidebar)` — selection, keyboard nav, and a11y come for free; `app_layout` pulls `data/sidebar`, per the "may compose data" note), the right sidebar and center are app elements (the right side is a details pane, not a list). Each visible sidebar renders a `strip_height` header strip with an end-aligned ghost icon toggle (`IconRole::PanelLeft`/`PanelRight` — new roles this unit: Segoe `DockLeft`/`DockRight` E90C/E90D per the MDL2 table, Lucide `panel-left`/`panel-right` bundled, freedesktop `sidebar-expand-*` → `sidebar-show-symbolic` cascade); `LayoutState` holds visibility + pixel widths with 160/480 px drag clamps (menu-cap px precedent); the right handle inverts the delta so dragging left grows it. `app_layout` pulls only core's `button` + `data/sidebar`; the facade `layout` feature re-requests `full` (core/data workspace deps are now `default-features = false`). 5 headless tests in `crates/layout/tests/app_layout.rs`: defaults, toggling via the state API, the header toggle button (clicked at metric-derived coordinates — gpui dispatch lesson from L1 applies to `on_click` too), seam resize + both clamps with no drift, and the inverted right seam. **Follow-up (2026-11-01):** the left sidebar is now the data crate's `Sidebar` component itself (`.left_sidebar(sidebar)` — selection, keyboard nav, and a11y come free; `app_layout` pulls `data/sidebar`), the right sidebar stays a free element (a details pane is not a list), and `Sidebar` gained a `sidebar-{id}` debug selector for headless tests |
+| L2 | layout | Shell ✅ Landed (2026-11-01) | The bootstrap shell: left sidebar region (on by default) + center + right sidebar region (off by default). Sidebar toggle in each sidebar's header, drag-resize widths through `ResizeHandle`; visibility and widths live on an application-owned `LayoutState` (the `InputState` pattern: `set_left_sidebar_visible` / `set_right_sidebar_visible` / `is_*` readers). The center region hosts the `Dock`. Shipped so: the left sidebar is the data crate's `Sidebar` component (`.left_sidebar(sidebar)` — selection, keyboard nav, and a11y come for free; `shell` pulls `data/sidebar`, per the "may compose data" note), the right sidebar and center are app elements (the right side is a details pane, not a list); `Sidebar` gained a `sidebar-{id}` debug selector for headless tests. Each visible sidebar renders a `strip_height` header strip with an end-aligned ghost icon toggle (`IconRole::PanelLeft`/`PanelRight` — new roles this unit: Segoe `DockLeft`/`DockRight` E90C/E90D per the MDL2 table, Lucide `panel-left`/`panel-right` bundled, freedesktop `sidebar-expand-*` → `sidebar-show-symbolic` cascade); `LayoutState` holds visibility + pixel widths with 160/480 px drag clamps (menu-cap px precedent); the right handle inverts the delta so dragging left grows it. `shell` pulls only core's `button` + `data/sidebar`; the facade `layout` feature re-requests `full` (core/data workspace deps are now `default-features = false`). The shell always paints the window frame around itself (L2.5), so it must be the window's root. 5 headless tests in `crates/layout/tests/shell.rs`: defaults, toggling via the state API, the header toggle button (clicked at metric-derived coordinates — gpui dispatch lesson from L1 applies to `on_click` too), seam resize + both clamps with no drift, and the inverted right seam |
 | L3 | layout | Dock | The center pane tree, controlled: `DockState` = `Pane { tabs, active }` or `Split { axis, ratio, a, b }`; panels are registered descriptors (`id` + view builder); add / close / activate are plain state ops; a pane emptied by closing its last tab collapses its split. Pane headers show titles, the active tab's close button, and a context menu (via core `ContextMenu`). |
 | L4 | layout | Dock drag-to-split | Dragging a tab: drop on a pane's edge splits a new pane there; drop on a pane's center moves the tab into that pane; a pane emptied by the move collapses. Edge drop zones paint from theme tokens while a drag is live. Split/merge go through the same `DockState` ops L3 exposed — the drag is interaction, not a second API. |
+| L2.5 | layout | window frame ✅ Landed (2026-11-01) | `window_frame::frame(child, window, cx)` — the client-side window frame for windows the OS does not decorate: under `Decorations::Server` (macOS, Windows, KDE, X11) it passes the child through untouched; under `Decorations::Client` (Wayland/GNOME) it insets the content, draws the hairline border and `Radius::overlay` corners (tiled sides stay square and lose their band), casts the dialog elevation's shadow dimmed to 0.7× when the window is inactive, and turns a 4 px band inside each live edge into resize hits (`start_window_resize`, edge cursors; a maximized window counts as flush everywhere). Requires a transparent window background, and must be the window's root — the bands hit-test against `Window::window_bounds`. **The `Shell` applies it by default**, so the module ships ungated — no separate feature. Adapted from bezel's `window::frame` + gpui-kit's `WindowBorder` (D15/D20), simplified to one inset band and theme-owned tokens |
 | L5 | layout | Sidebar auto-open | Panels declare `needs_right_sidebar` on their descriptor; activating such a panel opens the right sidebar; closing it leaves visibility to the user. The gallery gains a workspace-style shell page — the bootstrap example apps copy. |
 
 Deferred until a real need: layout persistence/serialization, pane zoom (maximize one pane), a bottom dock, collapse-to-edge docks, floating windows, drag between windows.
@@ -304,7 +305,7 @@ Deferred until a real need: layout persistence/serialization, pane zoom (maximiz
 | E+ — motion | Unit 14 (§6): per-component passes, each a few lines on gpui's own primitives — forwarding, Switch thumb, Toast slide, Dialog scrim, Progress cap | ✅ Landed (2026-10-30), each pass reviewed in the gallery; reduce-motion snaps gpui-side with the flag forwarded |
 | F — platforms + data | ✅ Landed (2026-10-30): `crates/data` (List, Tree, Tabs, Sidebar), the Linux theme sources (Omarchy/KDE/GNOME), the Windows source, the Segoe Fluent + freedesktop icon resolvers, plus per-platform elevation stacks (D24, 2026-11-01) | Remaining acceptance: side-by-side gallery screenshots — a Linux run (Omarchy/KDE/GNOME) and the first Windows hardware build |
 | G — migration additions (§6.3) | Waves M1–M2: Badge, Select, Segmented, Context menu, Empty state, password + multiline input, Avatar image, then M9+ → 0.1 | Each unit through the review gate; each wave unblocks a real signed screen |
-| H — layout crate (§6.4) | ResizeHandle, AppLayout bootstrap (left sidebar on, right sidebar off, center dock), Dock with drag-to-split, panel-declared sidebar auto-open | Each unit through the review gate; the gallery workspace page doubles as the bootstrap example apps copy |
+| H — layout crate (§6.4) | ResizeHandle, Shell bootstrap (left sidebar on, right sidebar off, center dock) + the client-side window frame, Dock with drag-to-split, panel-declared sidebar auto-open | Each unit through the review gate; the gallery workspace page doubles as the bootstrap example apps copy |
 
 Gate for every phase: `cargo fmt --check`, `cargo clippy --workspace --all-targets -- -D warnings`, `cargo test`, gallery smoke run.
 
@@ -374,6 +375,6 @@ Dropped from rev 3: D2, D5, D9 (port-era decisions); the review gate returns in
 6. ~~Unit 14 — motion, per component (§6 row 14, D21)~~ ✅ Landed in five passes (2026-10-30): (a) theme `reduce_motion` → `cx.set_reduce_motion` in `reapply`; (b) Switch thumb `with_spring`; (c) Toast 8 px slide-in; (d) Dialog scrim enters with the panel; (e) Progress 30 fps cap. Exits and hover washes stay deferred (§6 deferred list).
 7. ~~Phase F, data first~~ ✅ data complete (2026-10-30) — `crates/data` opened with List, then Tree, Tabs, Sidebar (the dead `sheet` feature dropped from core along the way; Table dropped from the roadmap). Also extracted `crates/utils` (2026-10-30): `h_flex`/`v_flex` (core's `common` re-exports them), `focus_handle` (the namespaced keyed handle, 8 call sites), `focus_ring` (7 sites), `adjacent_selectable` + `nav_key` (4 sites), and the selectable-row paint helpers `selectable_label_color`/`paint_selectable_row` (3 sites, reading `&Theme` directly — no intermediate color struct), plus the `StyledExt` trait (`refine_style` — adapted from gpui-kit `base`, D15 — replacing the per-component `style().refine` pattern; 5 sites) — `core` and `data` depend on it; the facade doesn't re-export it. **Linux theme sources landed (2026-10-30)**: Omarchy (colors.toml parse + state-dir detection + inotify on `current`), KDE (kdeglobals `[Colors:*]` + AccentColor + `~/.config` inotify), GNOME/generic (portal `ReadAll` + `SettingChanged` via zbus 5 blocking on its own thread, gsettings fallback with the libadwaita accent table) — `SourceKind::Omarchy/Kde/Gnome`, detection cascade Omarchy → KDE → portal → fallback, all parsers fixture-tested on every OS and the Linux build compile-checked via `cargo check --target x86_64-unknown-linux-gnu`. **Windows source + icon resolvers landed (2026-10-30)**: `SourceKind::Windows` (WinRT `UISettings` + `Personalize` fallback + `ColorValuesChanged`/`HighContrastChanged`, §5.3), the Segoe Fluent codepoint renderer, and the freedesktop theme walker (§4.4); the WinRT surface was verified against the real `windows` 0.62 bindings via a standalone cross-check (gpui's own manifest build needs llvm-rc from macOS). Remaining Phase F: **side-by-side gallery screenshots per platform** — Omarchy/KDE/GNOME need a Linux run, Windows needs its first hardware build. NumberInput stays deferred until needed; multiline landed as §6.3 M7 (2026-11-01).
 8. Then — Phase G is the migration additions (§6.3): Badge ✅, Select ✅, Segmented control ✅, Context menu ✅, Empty state ✅, password input ✅, multiline textarea ✅, then Avatar image (M8) — each unblocks a concrete signed screen. Pickers (Calendar/DatePicker, TimeField, ColorPicker) stay decided-at-unit-time. `crates/editor` starts when file viewing (M15) is reached.
-9. Then — the layout crate (§6.4): ResizeHandle ✅, AppLayout ✅, the center Dock with drag-to-split, and panel-declared sidebar auto-open — each through the review gate, with signed's `crates/dock` as the usage reference and the gallery workspace page as the example. Order against M9+ is decided when the crate starts.
+9. Then — the layout crate (§6.4): ResizeHandle ✅, Shell ✅, window frame ✅, the center Dock with drag-to-split, and panel-declared sidebar auto-open — each through the review gate, with signed's `crates/dock` as the usage reference and the gallery workspace page as the example. Order against M9+ is decided when the crate starts.
 
 Batched polish candidates between units: scrollbar auto-hide + horizontal thumb, `Undo`/`Redo` menu events.