Merge origin/main (6f52cc50, the squash of upstream pull request 471) into w/form-controls

Both sides added a kind of floating object (equation, form control); both are kept everywhere.
ROADMAP.md: header combined (form controls first, then equations), catalog 281 / 296 as `cargo xtask parity` measures, the form-controls progress-log and revision rows above main's equation rows.
crates/engine/src/cmd.rs: both spec lists (controls and equation).
crates/engine/src/cmd/extra.rs: the arrange params docs list both kinds.
crates/engine/src/cmd/extra/objects.rs: main's `found` match and `anchors_of` on ObjKind gain the Control arms; the unlocked check takes the parsed kind directly.
crates/engine/src/cmd/insert.rs: the object params docs and the kind error name both kinds.
crates/engine/src/tests.rs: both test modules.
crates/engine/src/tests/objects.rs: every_kind returns six objects (equation at L18, slider at P18) and the anchor lists carry both.
crates/model/src/features.rs: ObjKind has Equation and Control, ALL lists six kinds, name() both.
crates/model/src/sheet.rs: both imports, both accessor arms, the order test inserts equations (6, 8) and controls (13, 15) and documents controls after slicers with equations counted as shapes.
crates/model/src/workbook.rs: main's refresh_equations and this branch's free-id doc comment.
crates/ui-egui/src/chartview.rs: both doc comments combined.
crates/ui-egui/src/objects.rs: both OpenAction variants and arms.
crates/ui-egui/src/ribbon/insert.rs: the import list is the union.
docs/control-protocol.md: the kind list names equation and control; main's equation sentences and this branch's form-controls sentence.
docs/file-format-parity.md: header combined; the xlsx row carries both additions; the form-controls revision row above main's equation rows.
docs/parity-checklist.md: regenerated with `cargo xtask parity` (281 / 296).
docs/target-app-parity.md: header combined; catalog 281 / 296; the Insert objects row carries both additions; the form-controls revision row (277 / 292 → 281 / 296) above main's.
docs/ui-parity.md: header combined with catalog 281 / 296; main's move-and-resize row with equations plus the form-controls row; the form-controls revision row above main's.

crates/engine/src/cmd.rs

@@ -6,6 +6,7 @@ pub mod controls;
 pub mod data;
 pub mod draw;
 pub mod edit;
+pub mod equation;
 pub mod extra;
 pub mod file;
 pub mod forecast;
@@ -41,7 +42,11 @@ pub struct CommandSpec {
     pub label: &'static str,
     /// Ribbon/menu placement, e.g. `["Home", "Font"]`. Empty = not in menus.
     pub menu: &'static [&'static str],
+    /// Portable notation: `Cmd` is ⌘ on macOS and Ctrl elsewhere.
     pub shortcut: Option<&'static str>,
+    /// macOS override when its key differs. Equal to `shortcut` marks a Mac-only shortcut
+    /// (Align Left/Center): other platforms show none. See [`CommandInfo::shortcut_for_platform`].
+    pub shortcut_mac: Option<&'static str>,
     pub params: &'static str,
     pub enabled: Enabled,
     pub run: Run,
@@ -55,12 +60,32 @@ pub struct CommandInfo {
     pub label: &'static str,
     pub menu: Vec<&'static str>,
     pub shortcut: Option<&'static str>,
+    pub shortcut_mac: Option<&'static str>,
     pub params: &'static str,
     pub enabled: bool,
     #[serde(skip_serializing_if = "Option::is_none")]
     pub disabled_reason: Option<String>,
 }
 
+impl CommandInfo {
+    /// Format the portable shortcut notation for the runtime operating system.
+    pub fn shortcut_for_platform(&self, mac: bool) -> Option<String> {
+        let keys = if mac {
+            self.shortcut_mac.or(self.shortcut)
+        } else if self.shortcut_mac.is_some() && self.shortcut_mac == self.shortcut {
+            // An identical Mac override marks a Mac-only display shortcut.
+            // The portable field remains unchanged for legacy CLI consumers.
+            None
+        } else {
+            self.shortcut
+        }?;
+        if mac {
+            return Some(keys.to_owned());
+        }
+        Some(keys.split('+').map(|part| if part == "Cmd" { "Ctrl" } else { part }).collect::<Vec<_>>().join("+"))
+    }
+}
+
 impl CommandSpec {
     pub fn info(&self, s: &Session) -> CommandInfo {
         let e = (self.enabled)(s);
@@ -69,6 +94,7 @@ impl CommandSpec {
             label: self.label,
             menu: self.menu.to_vec(),
             shortcut: self.shortcut,
+            shortcut_mac: self.shortcut_mac,
             params: self.params,
             enabled: e.is_ok(),
             disabled_reason: e.err(),
@@ -119,13 +145,13 @@ pub fn has_clipboard(s: &Session) -> std::result::Result<(), String> {
 
 macro_rules! cmd {
     ($id:literal, $label:literal, [$($m:literal),*], $sc:expr, $params:literal, $en:expr, $run:expr) => {
-        $crate::cmd::CommandSpec { id: $id, label: $label, menu: &[$($m),*], shortcut: $sc, params: $params, enabled: $en, run: $run, journal: true, undoable: true }
+        $crate::cmd::CommandSpec { id: $id, label: $label, menu: &[$($m),*], shortcut: $sc, shortcut_mac: None, params: $params, enabled: $en, run: $run, journal: true, undoable: true }
     };
     (query $id:literal, $label:literal, [$($m:literal),*], $sc:expr, $params:literal, $en:expr, $run:expr) => {
-        $crate::cmd::CommandSpec { id: $id, label: $label, menu: &[$($m),*], shortcut: $sc, params: $params, enabled: $en, run: $run, journal: false, undoable: false }
+        $crate::cmd::CommandSpec { id: $id, label: $label, menu: &[$($m),*], shortcut: $sc, shortcut_mac: None, params: $params, enabled: $en, run: $run, journal: false, undoable: false }
     };
     (noundo $id:literal, $label:literal, [$($m:literal),*], $sc:expr, $params:literal, $en:expr, $run:expr) => {
-        $crate::cmd::CommandSpec { id: $id, label: $label, menu: &[$($m),*], shortcut: $sc, params: $params, enabled: $en, run: $run, journal: true, undoable: false }
+        $crate::cmd::CommandSpec { id: $id, label: $label, menu: &[$($m),*], shortcut: $sc, shortcut_mac: None, params: $params, enabled: $en, run: $run, journal: true, undoable: false }
     };
 }
 pub(crate) use cmd;
@@ -140,6 +166,7 @@ pub fn command_specs() -> &'static [CommandSpec] {
         v.extend(sheet::specs());
         v.extend(insert::specs());
         v.extend(controls::specs());
+        v.extend(equation::specs());
         v.extend(data::specs());
         v.extend(formulas::specs());
         v.extend(review::specs());
@@ -182,6 +209,7 @@ pub fn register_test_command(id: &'static str, run: Run) {
         label: id,
         menu: &[],
         shortcut: None,
+        shortcut_mac: None,
         params: "",
         enabled: |_| Ok(()),
         run,
@@ -199,6 +227,7 @@ pub(crate) fn register_undoable_test_command(id: &'static str, run: Run) {
         label: id,
         menu: &[],
         shortcut: None,
+        shortcut_mac: None,
         params: "",
         enabled: |_| Ok(()),
         run,
@@ -376,6 +405,9 @@ pub(crate) fn commit<R>(d: &mut DocState, f: impl FnOnce(&mut Ctx) -> Result<R>)
     };
     let r = f(&mut ctx)?;
     let Ctx { mut wb, changed, structural, mut fit_rows, protection_checked, edits, .. } = ctx;
+    // Equations whose source changed (or that arrived without a layout, as from a paste) are
+    // laid out here, so painting only ever reads the cache.
+    wb.refresh_equations();
     if !protection_checked {
         check_protection(&d.wb, &wb, &d.unlocked_ranges)?;
     }