feat(types): IVec2 + Rect 2D value types (#1)

Phase 1 of the fuller type-system proposal: two by-value spatial types
that lower to packed integers (no heap, copy like scalars).

- IVec2 — integer 2D vector, a pair of int packed into one i64, for tile
  and grid coordinates: make/zero/x/y/add/sub/scale/dot, the grid distance
  manhattan, equal, and to_vector (widen into the fixed-point Vector).
- Rect — axis-aligned rectangle, four Q16.16 fixed components packed into
  one i128, for HUD boxes and hitboxes: make/x/y/w/h, the derived
  right/bottom/center, and the contains (point) / intersects (overlap) tests.

Both are exact and deterministic, bit-identical on every platform. Vector
and Color already cover phase 1's other 2D primitives.

Wired end to end: emit_core llty (IVec2->i64, Rect->i128), emit_call
dispatch, the FRAGS list + reseeded seed, a selfhost test (types2d),
per-symbol docs + type pages + inventory, and the vocabulary/editor sync
(header, JetBrains, TextMate, LSP).

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

tools/editors/jetbrains/src/main/kotlin/io/ludic/ide/LudicTokens.kt

@@ -52,7 +52,7 @@ object LudicVocabulary {
         "enable", "disable", "match", "machine", "state", "become", "where",
         "and", "or", "not", "break", "continue", "new", "emit", "cancel", "try"
     )
-    val PRIMITIVES = setOf("int", "long", "fixed", "bool", "entity", "string", "pointer", "byte", "words", "fixeds", "pointers", "Vector", "void")
+    val PRIMITIVES = setOf("int", "long", "fixed", "bool", "entity", "string", "pointer", "byte", "words", "fixeds", "pointers", "Vector", "IVec2", "Rect", "void")
     val PHASES = setOf("Start", "Input", "FixedUpdate", "Update", "LateUpdate", "Render")
     val WIDGETS = setOf("panel", "col", "row", "label", "button", "image", "spacer")
 

tools/editors/shared/ludic.tmLanguage.json

@@ -177,7 +177,7 @@
         { "name": "keyword.other.clause.ludic", "match": "\\b(phase|query|on)\\b" },
         { "name": "keyword.other.ludic", "match": "\\b(import|extern)\\b" },
         { "name": "storage.type.ludic", "match": "\\b(program|property|model|enum|ui|const|var|let|function|handler|entry|state|test)\\b" },
-        { "name": "support.type.primitive.ludic", "match": "\\b(int|long|fixed|bool|entity|string|pointer|byte|words|fixeds|pointers|Vector|void)\\b" },
+        { "name": "support.type.primitive.ludic", "match": "\\b(int|long|fixed|bool|entity|string|pointer|byte|words|fixeds|pointers|Vector|IVec2|Rect|void)\\b" },
         { "name": "constant.language.boolean.ludic", "match": "\\b(true|false|null)\\b" },
         { "name": "constant.language.phase.ludic", "match": "\\b(Start|Input|FixedUpdate|Update|LateUpdate|Render)\\b" }
       ]

tools/editors/vscode/syntaxes/ludic.tmLanguage.json

@@ -177,7 +177,7 @@
         { "name": "keyword.other.clause.ludic", "match": "\\b(phase|query|on)\\b" },
         { "name": "keyword.other.ludic", "match": "\\b(import|extern)\\b" },
         { "name": "storage.type.ludic", "match": "\\b(program|property|model|enum|ui|const|var|let|function|handler|entry|state|test)\\b" },
-        { "name": "support.type.primitive.ludic", "match": "\\b(int|long|fixed|bool|entity|string|pointer|byte|words|fixeds|pointers|Vector|void)\\b" },
+        { "name": "support.type.primitive.ludic", "match": "\\b(int|long|fixed|bool|entity|string|pointer|byte|words|fixeds|pointers|Vector|IVec2|Rect|void)\\b" },
         { "name": "constant.language.boolean.ludic", "match": "\\b(true|false|null)\\b" },
         { "name": "constant.language.phase.ludic", "match": "\\b(Start|Input|FixedUpdate|Update|LateUpdate|Render)\\b" }
       ]