Put the rest of the selection settings on the Options card

Options → Selection already carried the pick box, the selection-area effect
and the grip visuals. Four settings behind it were finished, persisted and
reachable only by typing a system variable, and one more was a constant.

**Four that only needed a widget.** `SELECTIONEFFECT`, `SELECTIONPREVIEW`,
`PICKADD` and `PICKDRAG` are all wired end to end already. `SELECTIONEFFECT`
was the odd one: the card's own "Restore Defaults" button resets it, so it
could be turned off by a button and only turned back on from the command
line.

`SELECTIONPREVIEW` is a bitmask and gets one checkbox per bit, which is why
`set_preview_bit` exists rather than two inline expressions — the bits are
the thing this change is most able to get backwards.

The `PICKADD` checkbox is worded as AutoCAD words it, "use Shift to add to
selection", which is the *inverse* of the stored flag. That inversion is
commented at both ends; it reads as a bug otherwise.

**`GRIPOBJLIMIT`.** The limit past which a selection gets no grips arrived
with the selection work as a hardcoded 100, matching AutoCAD's default. It is
now a setting, a slider and a system variable, following `PICKBOX`'s path
exactly. AutoCAD's 0 means "no limit", which the old `>` comparison could not
express, so the read now guards on it — with a test, because zero is the one
value that would otherwise suppress every grip instead of allowing all of
them.

The slider covers 0..=1000, where every useful value lives; the sysvar takes
AutoCAD's full 0..=32767, and a larger value set from the command line parks
the handle at the end while the read-out keeps showing the real number.

**`SelectionPrefs`** replaces the `pick_box` parameter rather than adding
three more. `view_window` already took seventeen positional arguments, and
`pick_add` / `pick_drag_rect` are two adjacent `bool`s that would swap
silently at the call site.

**Two fixes found on the way.** `OPTIONS` and `OP` were registered for
autocomplete but never dispatched, so typing either answered "Unknown
command" and the dialog could only be opened from the start page. And the
`SELECTIONPREVIEW` doc comment had its bits the wrong way round — the code
reads `& 1` for the idle rollover and `& 2` for the in-command one, as
AutoCAD does — which would have put the two new checkboxes' labels backwards.

**Not done, deliberately.** `PICKFIRST` and `PICKAUTO` exist but are always
on, with no variable. `PICKSTYLE` is stored in the header and read by nobody
— group expansion decides from the group's own `selectable` flag — so an
"object grouping" checkbox would control nothing. Associative-hatch selection
does not exist as a selection behaviour. Each needs a behaviour change rather
than an exposure.

Of the ten new strings, en-US and el-GR are translated; the other nineteen
locales carry the English text. Composing them from existing keys, the way
el-GR composes the neighbouring labels, only works for one of the ten —
there is no existing key for "limit", "unlimited", "shift", "rectangle" or
"lasso", and "Grips: Objects" as the label of a numeric limit would be worse
than an untranslated string.

Co-Authored-By: Claude Opus 5 <[email protected]>

src/ui/window/options.rs

@@ -15,6 +15,24 @@ pub enum OptionsTab {
     Selection,
 }
 
+/// The Selection-card settings that live on `UserSettings` rather than on the
+/// model-space theme.
+///
+/// Gathered into one value instead of four more positional parameters: the
+/// function already takes seventeen, and `pick_add` / `pick_drag_rect` are two
+/// adjacent `bool`s that would swap silently at the call site.
+#[derive(Clone, Copy)]
+pub struct SelectionPrefs {
+    /// PICKBOX, 0..=50.
+    pub pick_box: i32,
+    /// PICKADD: true = a click adds to the selection.
+    pub pick_add: bool,
+    /// PICKDRAG: true = press-drag draws a rectangle instead of a lasso.
+    pub pick_drag_rect: bool,
+    /// GRIPOBJLIMIT, 0..=32767; 0 = no limit.
+    pub grip_object_limit: i32,
+}
+
 #[derive(Clone, Debug, PartialEq, Eq)]
 struct Labelled<T> {
     value: T,
@@ -36,7 +54,7 @@ pub fn view_window<'a>(
     language: crate::i18n::Language,
     active_tab: OptionsTab,
     cursor_size: i32,
-    pick_box: i32,
+    selection: SelectionPrefs,
     cursor_type: CursorType,
     crosshair_color: Option<[u8; 3]>,
     crosshair_color_input: &'a str,
@@ -544,10 +562,12 @@ pub fn view_window<'a>(
         Space::new().height(10),
         row![
             text(crate::t!("Pick box size")).size(12).width(140),
-            slider(0..=50, pick_box.clamp(0, 50), Message::PickBoxChanged)
+            slider(0..=50, selection.pick_box.clamp(0, 50), Message::PickBoxChanged)
                 .step(1)
                 .width(Fill),
-            text(pick_box.clamp(0, 50).to_string()).size(11).width(44),
+            text(selection.pick_box.clamp(0, 50).to_string())
+                .size(11)
+                .width(44),
         ]
         .spacing(10)
         .align_y(iced::Center),
@@ -558,6 +578,31 @@ pub fn view_window<'a>(
         .size(11)
         .width(sizing.width),
         Space::new().height(24),
+        text(crate::t!("Selection Modes")).size(15),
+        Space::new().height(10),
+        row![
+            // Worded the way AutoCAD words it, which is the inverse of PICKADD:
+            // ticked means a plain click replaces the selection and Shift adds.
+            iced::widget::checkbox(!selection.pick_add)
+                .on_toggle(Message::ShiftToAddToggled)
+                .size(15),
+            text(crate::t!("Use Shift to add to selection (PICKADD)")).size(12),
+        ]
+        .spacing(8)
+        .align_y(iced::Center),
+        Space::new().height(10),
+        row![
+            iced::widget::checkbox(selection.pick_drag_rect)
+                .on_toggle(Message::PickDragRectToggled)
+                .size(15),
+            text(crate::t!(
+                "Press and drag draws a rectangle instead of a lasso (PICKDRAG)"
+            ))
+            .size(12),
+        ]
+        .spacing(8)
+        .align_y(iced::Center),
+        Space::new().height(24),
         row![
             text(crate::t!("Visual Effect Settings")).size(15),
             Space::new().width(Fill),
@@ -626,6 +671,15 @@ pub fn view_window<'a>(
         .spacing(10)
         .align_y(iced::Center),
         Space::new().height(10),
+        row![
+            iced::widget::checkbox(model_space.selection_effect)
+                .on_toggle(Message::SelectionEffectToggled)
+                .size(15),
+            text(crate::t!("Show selection effect (SELECTIONEFFECT)")).size(12),
+        ]
+        .spacing(8)
+        .align_y(iced::Center),
+        Space::new().height(10),
         row![
             text(crate::t!("Selection highlight color")).size(12).width(140),
             iced::widget::pick_list(
@@ -639,6 +693,34 @@ pub fn view_window<'a>(
         .spacing(10)
         .align_y(iced::Center),
         Space::new().height(24),
+        text(crate::t!("Preview")).size(15),
+        Space::new().height(10),
+        row![
+            // SELECTIONPREVIEW is a bitmask; bit 1 is the idle rollover and
+            // bit 2 the one that runs while a command is gathering objects.
+            iced::widget::checkbox(model_space.selection_preview & 1 != 0)
+                .on_toggle(Message::SelectionPreviewIdleToggled)
+                .size(15),
+            text(crate::t!("Preview selection when no command is active")).size(12),
+        ]
+        .spacing(8)
+        .align_y(iced::Center),
+        Space::new().height(10),
+        row![
+            iced::widget::checkbox(model_space.selection_preview & 2 != 0)
+                .on_toggle(Message::SelectionPreviewCommandToggled)
+                .size(15),
+            text(crate::t!("Preview selection during a command")).size(12),
+        ]
+        .spacing(8)
+        .align_y(iced::Center),
+        Space::new().height(6),
+        text(crate::t!(
+            "Highlights the object under the cursor before it is picked (SELECTIONPREVIEW)."
+        ))
+        .size(11)
+        .width(sizing.width),
+        Space::new().height(24),
         text(crate::t!("Grip Settings")).size(15),
         Space::new().height(10),
         row![
@@ -657,6 +739,36 @@ pub fn view_window<'a>(
         .spacing(10)
         .align_y(iced::Center),
         Space::new().height(10),
+        row![
+            text(crate::t!("Object limit for grips")).size(12).width(140),
+            // The slider covers the range where the setting is worth changing;
+            // the sysvar accepts AutoCAD's full 0..=32767, so a larger value
+            // set from the command line parks the handle at the end while the
+            // read-out keeps showing the real number.
+            slider(
+                0..=1000,
+                selection.grip_object_limit.clamp(0, 1000),
+                Message::GripObjectLimitChanged,
+            )
+            .step(1)
+            .width(Fill),
+            text(if selection.grip_object_limit == 0 {
+                crate::t!("Unlimited").into_owned()
+            } else {
+                selection.grip_object_limit.to_string()
+            })
+            .size(11)
+            .width(44),
+        ]
+        .spacing(10)
+        .align_y(iced::Center),
+        Space::new().height(6),
+        text(crate::t!(
+            "Past this many selected objects no grips are drawn; 0 removes the limit (GRIPOBJLIMIT)."
+        ))
+        .size(11)
+        .width(sizing.width),
+        Space::new().height(10),
         row![
             text(crate::t!("Unselected grip color")).size(12).width(140),
             iced::widget::pick_list(