Merge branch 'main' into feature/parametric-constraint-system

Brings in 54 commits from origin/main: a selection-performance overhaul,
surface thickening, GPU-native wide/tapered stroke rendering, continued
ocs_doc_api evolution, and assorted fixes/polish (block double-click
editing, DWG hatch/database repair, clipboard, collapsible Properties
sections).

Six real conflicts, all where this branch had independently re-applied
a fix upstream later revised or already carried natively:

- src/app/automation.rs, src/app/command_driver.rs: combined both
  sides — kept this branch's sketch-constraint/named-parameter loading
  on "new"/"open", adopted main's Scene::clear()/material_base_dir and
  its newer rebuild_derived_caches() over the older bump_geometry().
  Scene::clear() (src/scene/entity.rs) now also resets
  sketch_constraints/named_parameters, so every caller gets this for
  free instead of each call site repeating it.
- src/io/mod.rs, src/scene/render_graph.rs: adopted main's design
  outright (commit 973af87d, authored by Hakan directly) — a large
  MINSERT is no longer purged as "corrupt" at load, only its rendering
  is bounded, preserving the source data. This branch's own earlier
  design (reject at load) predates that revision.
- src/scene/pipeline/mesh_gpu.rs: adopted main's valid_rgba_size()
  guard (a real robustness improvement over this branch's version).
- src/snap.rs: replaced wholesale with main's version — this branch's
  copy was an explicit verbatim snapshot from an earlier upstream PR
  (commit 4c264b8c) with zero constraint-system-specific content, and
  main has since evolved it considerably further.

Also removed two now-dead duplicates the merge surfaced without a
conflict marker (both branches had independently fixed the same
things): the OPTIONS/OP command dispatch/autocomplete entries, and
automation.rs's open_finalizes_and_purges_like_the_ui_open_path test
(kept main's version, which covers strictly more: solid_models/
material_base_dir reset on "new").

Full workspace suite passes (812 lib tests + this branch's own 24
constraint/persistence integration tests) except the one pre-existing,
unrelated font-test failure already present on main. Zero clippy
findings in the hand-written merge resolution itself; the ~1,171
warnings clippy reports are pre-existing in the 54 absorbed commits,
not introduced here.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

src/app/settings.rs

@@ -145,6 +145,9 @@ pub(crate) fn snaps_from_osmode(osmode: i32) -> (Vec<SnapType>, bool) {
     (modes, osmode & OSMODE_SUPPRESS == 0)
 }
 
+/// GRIPOBJLIMIT default: past this many selected objects, no grips are drawn.
+pub const DEFAULT_GRIP_OBJECT_LIMIT: i32 = 100;
+
 /// The "settings" section of the consolidated config ([`crate::app::config`]).
 /// Field defaults mirror the app's in-code defaults so a missing key restores
 /// the value the app boots with.
@@ -160,6 +163,13 @@ pub struct UserSettings {
     pub cursor_size: i32,
     /// PICKBOX: normalized visible-box and click-aperture size.
     pub pick_box: i32,
+    /// When true, double-clicking a block reference starts REFEDIT instead of BEDIT.
+    pub double_click_block_refedit: bool,
+    /// When true, double-clicking a block with attributes opens ATTEDIT.
+    pub double_click_block_attedit: bool,
+    /// GRIPOBJLIMIT: past this many selected objects, no grips are drawn at
+    /// all. 0 means no limit. The drawing header carries no slot for it.
+    pub grip_object_limit: i32,
     /// CURSORTYPE: crosshair or the platform pointer over the drawing.
     pub cursor_type: CursorType,
     /// Explicit crosshair RGB. `None` keeps automatic background contrast.
@@ -324,6 +334,9 @@ impl Default for UserSettings {
             zoom_factor: 60,
             cursor_size: 5,
             pick_box: 3,
+            double_click_block_refedit: false,
+            double_click_block_attedit: true,
+            grip_object_limit: DEFAULT_GRIP_OBJECT_LIMIT,
             cursor_type: CursorType::Crosshair,
             crosshair_color: None,
             lineweight_display_scale: 100,