Make a large selection scale with the drawing

Selecting a whole drawing was unusable on a 186 468-entity file. Four costs
scaled with the selection where they did not have to.

Every selected handle triggered a walk of the entire document to find LEADERs
pointing at it. On the file this came from, selecting 471 583 entities in a
585 786-entity drawing did not finish inside eight minutes. A reverse index
built once per geometry epoch answers the same question; a test asserts it
returns exactly what the walk returned, including the case of two leaders on
one annotation.

Group expansion asked the selection about every group: for each selected
handle it scanned each group's own member list. Asking each group once
whether it holds anything selected turns that around.

Selecting and deselecting went one entity at a time, and `deselect_entity`
rebuilt the ordered list with a `retain` per handle, so removing N of M
walked the order list N times. Both now take a slice.

Grips were built for every selected entity. AutoCAD stops at GRIPOBJLIMIT,
and the DWG header does not carry the variable, so its default of 100 stands
in for it.

The remaining two commits are measurement: `select-commit` reports the phases
of a selection separately, which is what showed the bulk paths had been added
to the press-drag branch while a click-move-click window goes through a
different one entirely.

src/app/update/viewport.rs

@@ -4093,6 +4093,10 @@ impl OpenCADStudio {
                                         aabb
                                     },
                                 );
+                        // A 186 k-entity box selection sits at ~800 ms in this
+                        // handler and two guesses about which step owns it have
+                        // both been wrong. Split it.
+                        let t_sel = crate::perf::enabled().then(Instant::now);
                         let area_candidates = self.tabs[i].scene.interaction_candidates_in_aabb(
                             all_wires,
                             world_aabb,
@@ -4101,6 +4105,9 @@ impl OpenCADStudio {
                             eye,
                             bounds,
                         );
+                        let cand_ms = t_sel
+                            .map_or(0.0, |t| t.elapsed().as_secs_f64() * 1000.0);
+                        let t_hit = crate::perf::enabled().then(Instant::now);
                         let candidate_handles = self.tabs[i]
                             .scene
                             .interaction_candidate_handles(&area_candidates);
@@ -4161,20 +4168,30 @@ impl OpenCADStudio {
                         // selection, Shift+box removes the boxed
                         // entities. Esc / empty-space click still clears.
                         // PICKADD 0 (#226): a plain box REPLACES.
+                        let hit_ms = t_hit
+                            .map_or(0.0, |t| t.elapsed().as_secs_f64() * 1000.0);
+                        let t_apply = crate::perf::enabled().then(Instant::now);
                         if self.shift_down || self.select_remove_mode {
-                            for h in &handles {
-                                self.tabs[i].scene.deselect_entity(*h);
-                            }
+                            self.tabs[i].scene.deselect_entities(&handles);
                         } else {
                             if !selection_pick_add && !handles.is_empty() {
                                 self.tabs[i].scene.deselect_all();
                             }
-                            for h in &handles {
-                                self.tabs[i].scene.select_entity(*h, false);
-                            }
+                            self.tabs[i].scene.select_entities(&handles);
                             self.tabs[i].scene.expand_selection_for_groups(&handles);
                         }
+                        let apply_ms = t_apply
+                            .map_or(0.0, |t| t.elapsed().as_secs_f64() * 1000.0);
+                        let t_props = crate::perf::enabled().then(Instant::now);
                         self.refresh_properties();
+                        if crate::perf::enabled() {
+                            crate::perf_record!(
+                                "[perf] select-commit kind=drag-box candidates={cand_ms:.1}ms \
+hit={hit_ms:.1}ms apply={apply_ms:.1}ms properties={:.1}ms picked={}",
+                                t_props.map_or(0.0, |t| t.elapsed().as_secs_f64() * 1000.0),
+                                handles.len(),
+                            );
+                        }
                         selection_just_completed = true;
                     }
                 } else {
@@ -4208,9 +4225,7 @@ impl OpenCADStudio {
                     // leaves the current selection untouched so a stray
                     // drag never discards hard-won picks.
                     if self.shift_down || self.select_remove_mode {
-                        for h in &handles {
-                            self.tabs[i].scene.deselect_entity(*h);
-                        }
+                        self.tabs[i].scene.deselect_entities(&handles);
                     } else {
                         // PICKADD 0 (#226): a plain marquee REPLACES
                         // the selection (empty results still leave it
@@ -4218,9 +4233,7 @@ impl OpenCADStudio {
                         if !selection_pick_add && !handles.is_empty() {
                             self.tabs[i].scene.deselect_all();
                         }
-                        for h in &handles {
-                            self.tabs[i].scene.select_entity(*h, false);
-                        }
+                        self.tabs[i].scene.select_entities(&handles);
                         self.tabs[i].scene.expand_selection_for_groups(&handles);
                     }
                     self.refresh_properties();
@@ -4454,6 +4467,10 @@ impl OpenCADStudio {
                                 aabb
                             },
                         );
+                    // This is the path a click-move-click window takes, as
+                    // opposed to a press-drag; it is the one a large selection
+                    // actually goes through.
+                    let t_sel = crate::perf::enabled().then(Instant::now);
                     let area_candidates = self.tabs[i].scene.interaction_candidates_in_aabb(
                         all_wires,
                         world_aabb,
@@ -4462,6 +4479,9 @@ impl OpenCADStudio {
                         eye,
                         bounds,
                     );
+                    let cand_ms =
+                        t_sel.map_or(0.0, |t| t.elapsed().as_secs_f64() * 1000.0);
+                    let t_hit = crate::perf::enabled().then(Instant::now);
                     let candidate_handles = self.tabs[i]
                         .scene
                         .interaction_candidate_handles(&area_candidates);
@@ -4517,27 +4537,39 @@ impl OpenCADStudio {
                         bounds,
                         candidate_handles.as_ref(),
                     ));
+                    let hit_ms = t_hit.map_or(0.0, |t| t.elapsed().as_secs_f64() * 1000.0);
+                    let t_filter = crate::perf::enabled().then(Instant::now);
                     // Selection filter: keep only allowed types.
                     handles.retain(|&h| self.tabs[i].scene.passes_selection_filter(h));
+                    let filter_ms =
+                        t_filter.map_or(0.0, |t| t.elapsed().as_secs_f64() * 1000.0);
+                    let t_apply = crate::perf::enabled().then(Instant::now);
                     // Accumulate (issue #83): a plain box adds to the
                     // current selection, Shift+box removes the boxed
                     // entities. An empty box leaves the selection alone
                     // so an accidental empty drag never discards it.
                     // PICKADD 0 (#226): a plain box REPLACES instead.
                     if self.shift_down || self.select_remove_mode {
-                        for h in &handles {
-                            self.tabs[i].scene.deselect_entity(*h);
-                        }
+                        self.tabs[i].scene.deselect_entities(&handles);
                     } else {
                         if !selection_pick_add && !handles.is_empty() {
                             self.tabs[i].scene.deselect_all();
                         }
-                        for h in &handles {
-                            self.tabs[i].scene.select_entity(*h, false);
-                        }
+                        self.tabs[i].scene.select_entities(&handles);
                         self.tabs[i].scene.expand_selection_for_groups(&handles);
                     }
+                    let apply_ms =
+                        t_apply.map_or(0.0, |t| t.elapsed().as_secs_f64() * 1000.0);
+                    let t_props = crate::perf::enabled().then(Instant::now);
                     self.refresh_properties();
+                    if crate::perf::enabled() {
+                        crate::perf_record!(
+                            "[perf] select-commit kind=window candidates={cand_ms:.1}ms \
+hit={hit_ms:.1}ms filter={filter_ms:.1}ms apply={apply_ms:.1}ms properties={:.1}ms picked={}",
+                            t_props.map_or(0.0, |t| t.elapsed().as_secs_f64() * 1000.0),
+                            handles.len(),
+                        );
+                    }
                     let mut sel = self.tabs[i].scene.selection.borrow_mut();
                     sel.box_last = Some((a, p));
                     sel.box_last_crossing = crossing;