feat(commands): integrate standard CAD commands and fix behavior gaps

Broad pass over the command set: integrate missing commands, wire
previously-unreachable ribbon/menu buttons, and correct name/behaviour
mismatches. Every UI command token now resolves (real handler where the
infrastructure exists, an honest "not yet implemented" status otherwise).

New commands:
- Draw: 3DPOLY, 2D solid (SO/SOLID2D), HELIX, TRACE, SKETCH, DIMCENTER
  (DCE/CENTERMARK)
- Modify/inquiry: REVERSE, MEASUREGEOM (MEA), DBLIST
- Data/manage: BASE, OVERKILL (exact-duplicate removal), AUDIT (read-only
  integrity report), SETVAR (system-variable get/set), SCRIPT (.scr runner),
  FINDNONPURGEABLE

Behaviour fixes:
- LINE and SPLINE gain Close/Undo; AREA computes area/perimeter in f64
  (correct at large coordinates)
- ATTEDIT/ATE unified so the alias and the ribbon button open the
  interactive editor; -ATTEDIT is the command-line form
- Linear/aligned/radius/diameter dimensions gain a text override (Text) and
  text angle (Angle) option
- INSERT gains Scale/Rotate options; COPY gains an Array option
- LINETYPE SET sets the current entity linetype; SETBYLAYER resets overrides
- UNDO accepts a step count

Integrations: standard dimension/block aliases (DLI/DRA/DAN, BMAKE,
EXPORTPDF, DDIM), drafting-aid and screen toggles (GRID/SNAP/POLAR/OSNAP/
DSETTINGS/CLEANSCREEN/QUICKPROPERTIES), viewport tiling
(CASCADE/HORIZONTAL/VERTICAL/VPJOIN), and customization entry points
(CUI/ALIASEDIT).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/app/commands/mod.rs

@@ -200,6 +200,21 @@ impl OpenCADStudio {
 // excluded.
 inventory::submit!(crate::command::CommandRegistration {
     names: &[
+        // Drafting-aid / display toggles + customization entry points wired in the
+        // dispatch families (no interactive command module of their own).
+        "ALIASEDIT", "CLEANSCREEN", "CUI", "DSETTINGS", "GRID", "OSNAP", "POLAR",
+        "QUICKPROPERTIES", "SNAP",
+        // Viewport-arrangement shortcuts (delegate to VPORTS configurations).
+        "CASCADE", "HORIZONTAL", "VERTICAL", "VPJOIN",
+        // Standard aliases for existing commands.
+        "BMAKE", "EXPORTPDF", "DDIM",
+        // Inquiry: list the whole drawing database.
+        "DBLIST",
+        // Reset selected entities' overrides to follow their layer.
+        "SETBYLAYER",
+        // Remove duplicate objects; set drawing base point; audit integrity;
+        // read/write system variables.
+        "OVERKILL", "BASE", "AUDIT", "SETVAR", "SCRIPT", "SCR", "FINDNONPURGEABLE",
         "3DORBIT", "3O", "ABOUT", "ATTDISP", "ATTEXT", "BACKGROUND", "CDIMSTY", "CELTSCALE",
         "CHANGELOG", "CHPROP", "CLAYER", "CLEAR", "CLR", "COLORSCHEME", "COUNT", "DATAEXTRACTION",
         "DE", "DESELALL", "DESELECT", "DIMSTYLE", "DONATE", "DRAWORDER", "DWGPROP", "DWGPROPS",