feat(alias): centralize command aliases in user-editable ocad.pgp (#286/#288)

Command aliases (L→LINE, CC→COPYCLIP) were scattered across dispatch match
arms and CommandRegistration name arrays. Move them all into a single
user-editable file:

- assets/ocad.pgp: shipped default alias table (ALIAS,*COMMAND format),
  embedded and copied to config/ocad.pgp on first launch; only that user
  copy is read after. AA→AREA default closes #286.
- resolve_alias() rewrites the leading command token at the top of
  dispatch_command_inner, so aliases resolve for every path (families,
  plugins, Repeat menu). Args after the first space are untouched.
- Autocomplete hides alias keys and, when the whole input is an alias,
  surfaces its target command as the top (highlighted) suggestion so the
  highlight matches what Enter runs (AA→AREA, L→LINE).
- ALIASEDIT opens a new editor modal (add/edit/delete rows) with an Apply
  button; Apply persists to ocad.pgp, closing discards unapplied edits.
- Strip alias tokens from all 8 dispatch match-arm files and 71 module
  CommandRegistration arrays, keeping canonical/synonym/distinct-command
  names. ocad.pgp is now the sole source: deleting or remapping an alias
  there takes effect. CUI stays on the keyboard-shortcut panel.

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

src/app/commands/fileops.rs

@@ -70,7 +70,7 @@ impl OpenCADStudio {
                     }
                 }
             }
-            "UNDO" | "U" => return Some(Task::done(Message::Undo)),
+            "UNDO" => return Some(Task::done(Message::Undo)),
             "REDO" => return Some(Task::done(Message::Redo)),
             // OOPS — restore the objects removed by the most recent ERASE,
             // without undoing any work done since.
@@ -92,7 +92,7 @@ impl OpenCADStudio {
                 }
             }
             "CLEAR" | "CLR" => return Some(Task::done(Message::ClearScene)),
-            "WIREFRAME" | "VW" => return Some(Task::done(Message::SetWireframe(true))),
+            "WIREFRAME" => return Some(Task::done(Message::SetWireframe(true))),
             // Visual-style commands. OCS renders either a wireframe or a shaded
             // view; the named styles map onto the closest of the two and the
             // chosen style is reported so the mapping is explicit. (`SOLID` is
@@ -309,7 +309,7 @@ impl OpenCADStudio {
             "ORTHO" => return Some(Task::done(Message::ToggleOrtho)),
             "PARALLEL" => return Some(Task::done(Message::SetProjection(true))),
             "PERSP" => return Some(Task::done(Message::SetProjection(false))),
-            "LAYERS" | "LA" => return Some(Task::done(Message::ToggleLayers)),
+            "LAYERS" => return Some(Task::done(Message::ToggleLayers)),
 
             // SCRIPT <path> — run a command script: each non-blank, non-comment
             // line is fed through the same command path the `--script` startup