M1: keyboard shortcut parity suite and bindings

- A shortcut parity table (`crates/engine/src/shortcut_parity_tests.rs`): one row per shortcut in
  the public documentation (help-centre feature articles: keyboard layouts, text properties,
  alignment, frames, components, prototypes, plugins, keyboard navigation), with the macOS and the
  Windows/Linux keys, what handles it here (keymap command, held key/gesture listed in the panel,
  vector edit tool key, or missing), and a note in our own words. Rows the documentation is silent
  on pin today's keys, so every default binding is in the table.
  - 129 documented rows: 126 bound (110 before), 1 moved off a documented conflict (Run last
    plugin on Windows: the docs also give Ctrl+Alt+P to pixel preview; the plugin keeps
    Ctrl+Alt+Shift+P), 2 missing (moving the rotation origin with Alt+R; placing an object with
    Enter after choosing a tool from the toolbar), 2 kept by a platform (Ctrl+Space with some CJK
    input methods; F6 in browsers). 48 undocumented bindings pinned.
  - Tests: every row fires its command on both platforms and sits in the right shortcuts-panel tab;
    every default binding has a row; no binding uses a chord the OS keeps (Cmd+H/M/Q/Tab/Space,
    Ctrl+Space, screenshot keys on macOS; Alt+Space/Tab/F4, Ctrl+Esc, Ctrl+Alt+Delete, Linux
    workspace and VT keys); macOS keycaps show Cmd/Option glyphs only and Windows/Linux keycaps
    Ctrl/Alt words only; vector edit tool keys; counts pinned for the docs.
- Newly bound: A (Frame tool), Shift+' (pixel grid; Cmd+' kept, the articles disagree),
  Alt+Cmd+\ / Ctrl+Alt+\ (others' cursors in a live session), Ctrl+F6 (toolbar focus on
  Windows/Linux), Shift+Cmd+U (link text; Cmd+K kept), Cmd/Ctrl+] and [ (list levels while
  editing), Cmd/Ctrl+Backspace (ungroup), Alt+Space / Ctrl+Space (keyboard box selection; F8 kept,
  Cmd/Ctrl+arrows draw the box out), Ctrl+Shift+A / Ctrl+Alt+Shift+A (suggest auto layout),
  Ctrl+Alt+Cmd+K / Ctrl+Alt+Shift+K (go to main component).
- New commands: `view.multiplayerCursors {on?}` (View menu item, menu breadth 207/207),
  `view.pan {dx, dy, big?}` (arrows pan the view by 20 screen px, 200 with Shift, when nothing is
  selected; the canvas and MCP `key` both use it), `text.listIndent` / `text.listOutdent`.
- Behaviour: Control held while dragging suspends snapping on macOS too (Cmd/Ctrl already did);
  the presenter takes Space and N for the next frame, C for comments (Shift+C kept) and F for full
  screen, after the prototype's own key triggers; the paint bucket's tooltip shows Shift+B (B still
  works).
- Keyboard layouts: shortcuts follow the character typed, named as on a US keyboard. A symbol
  another layout types with Shift (`/` is Shift+7 on German keyboards) now counts without the
  Shift (canvas, text editing and F6 navigation share one lookup). Characters egui has no key for
  already arrive as the key at that position.
- Keyboard shortcuts panel: new rows for panning with the arrows, suspending snapping, moving along
  the toolbar, and the presentation keys, in the tabs the documentation groups them in (en/es
  strings).
- Docs: ui-parity.md gets a Keyboard shortcuts section with the counts; target-app-parity.md,
  ROADMAP.md, gaps.md (gap 4 landed list), mcp.md, parity-checklist.md (regenerated).

crates/engine/src/cmd/edit.rs

@@ -86,7 +86,7 @@ pub fn specs() -> Vec<CommandSpec> {
         spec!(
             "select.area",
             "Select area",
-            "{x, y, width, height (page units; a marquee from x, y), add? (toggle like a Shift marquee), deep? (nested layers, like Cmd/Ctrl)} → {selection}; with no box: draw one from the keyboard in the app (arrows move it, Shift+arrows size it, Enter selects, Escape cancels)",
+            "{x, y, width, height (page units; a marquee from x, y), add? (toggle like a Shift marquee), deep? (nested layers, like Cmd/Ctrl)} → {selection}; with no box: draw one from the keyboard in the app (arrows move it, Cmd/Ctrl+arrows or Shift+arrows size it, Enter selects, Escape cancels)",
             false,
             select_area
         ),

crates/engine/src/cmd/text.rs

@@ -402,6 +402,12 @@ pub fn specs() -> Vec<CommandSpec> {
                 ok()
             }
         ),
+        spec!("text.listIndent", "Indent list", "{}  while editing: the selected list items a level deeper", true, |s, _| {
+            Ok(json!({"changed": textedit::list_indent(s, false)?}))
+        }),
+        spec!("text.listOutdent", "Outdent list", "{}  while editing: the selected list items a level out", true, |s, _| {
+            Ok(json!({"changed": textedit::list_indent(s, true)?}))
+        }),
         spec!("text.edit.caret", "Set caret", "{index, extend?}", false, |s, p| {
             let i = req_num("text.edit.caret", p, "index")?.max(0.0) as usize;
             textedit::set_caret(s, i, boolean(p, "extend").unwrap_or(false))?;

crates/engine/src/cmd/view.rs

@@ -43,6 +43,20 @@ fn zoom_to(s: &mut Session, z: f64) -> Result<Value> {
     Ok(json!({"zoom": v.zoom}))
 }
 
+/// How far an arrow key pans the view with nothing selected (screen pixels; Shift: ten times).
+pub const PAN_STEP_PX: f64 = 20.0;
+
+/// `view.pan`: the arrow keys with nothing selected move the view by keyboard steps.
+fn pan(s: &mut Session, p: &Value) -> Result<Value> {
+    let step = if boolean(p, "big").unwrap_or(false) { PAN_STEP_PX * 10.0 } else { PAN_STEP_PX };
+    let dir = |k| num(p, k).filter(|v| v.is_finite()).unwrap_or(0.0).clamp(-100.0, 100.0) * step;
+    let (dx, dy) = (dir("dx"), dir("dy"));
+    let v = view(s)?;
+    // Scrolling moves the content; panning right shows what is to the right.
+    v.scroll(-dx, -dy, false);
+    Ok(json!({"cx": v.cx, "cy": v.cy}))
+}
+
 /// Figma's zoom steps.
 const STEPS: &[f64] = &[0.02, 0.03, 0.06, 0.13, 0.25, 0.5, 1.0, 2.0, 4.0, 8.0, 16.0, 32.0, 64.0, 128.0, 256.0];
 
@@ -192,6 +206,10 @@ pub fn specs() -> Vec<CommandSpec> {
         spec!("view.rulers", "Rulers", "{on?}", false, |s, p| flag(s, p, |v| &mut v.rulers)),
         spec!("view.slices", "Slices", "{on?}", false, |s, p| flag(s, p, |v| &mut v.show_slices)),
         spec!("view.comments", "Comments", "{on?}", false, |s, p| flag(s, p, |v| &mut v.comments)),
+        spec!("view.multiplayerCursors", "Multiplayer cursors", "{on?}  others' cursors in a live session", false, |s, p| {
+            flag(s, p, |v| &mut v.multiplayer_cursors)
+        }),
+        spec!("view.pan", "Pan the view", "{dx, dy (arrow-key steps, e.g. 1 or -1), big? (ten times as far, like Shift)}", false, pan),
         spec!("view.outlines", "Outlines", "{on?}", false, |s, p| flag(s, p, |v| &mut v.outlines)),
         spec!("view.outlinesSelection", "Outlines for selection", "{on?}  outline mode for the selected layers only", false, |s, p| {
             flag(s, p, |v| &mut v.outlines_selection)