fix(runtime): let per-edge borderDimColor=false override general dim (Ink parity, G16) (#44)

* fix(runtime): let per-edge borderDimColor=false override general dim (Ink parity, G16)

edgeDim now uses `?? generalDim` (nullish) instead of `|| dimAll`, so an explicit per-edge false wins — matching Ink render-border.ts:54. The five borderDimColor prop declarations in Box.ts are changed from bare `Boolean` to `{ type: Boolean, default: undefined }` so Vue does not boolean-coerce absent per-edge dim props to false (Vue only applies absent→false casting when no explicit default is provided), preserving the undefined sentinel needed for the nullish fallback.

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

* chore(parity): ledger — G16 pr-open, reconcile G14 merged

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

---------

Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>

packages/runtime/src/components/Box.ts

@@ -117,11 +117,21 @@ const BoxImpl = defineComponent({
     // Ink types borderStyle as `keyof Boxes | BoxStyle`; we mirror that here.
     borderStyle: [String, Object] as PropType<BorderStyle | BoxStyle>,
     borderColor: [String, Array],
-    borderDimColor: Boolean,
-    borderTopDimColor: Boolean,
-    borderBottomDimColor: Boolean,
-    borderLeftDimColor: Boolean,
-    borderRightDimColor: Boolean,
+    // `default: undefined` is intentional and load-bearing: Vue's boolean-casting
+    // rule coerces absent Boolean props to `false` only when there is no explicit
+    // default. Adding `default: undefined` suppresses that coercion so absent
+    // per-edge dim props arrive in the paint pass as `undefined`, not `false`.
+    // This lets `edgeDim = (perEdge ?? generalDim)` correctly fall back to the
+    // general value only when the per-edge prop was truly omitted — mirroring
+    // Ink render-border.ts:54 which uses real-undefined via React's prop model
+    // (G16). The `Boolean` type is kept so Vue still accepts bare-attribute
+    // `<Box borderDimColor>` in templates (coerces `""` → `true`) and passes
+    // TypeScript type-checking for consumers.
+    borderDimColor: { type: Boolean as PropType<boolean | undefined>, default: undefined },
+    borderTopDimColor: { type: Boolean as PropType<boolean | undefined>, default: undefined },
+    borderBottomDimColor: { type: Boolean as PropType<boolean | undefined>, default: undefined },
+    borderLeftDimColor: { type: Boolean as PropType<boolean | undefined>, default: undefined },
+    borderRightDimColor: { type: Boolean as PropType<boolean | undefined>, default: undefined },
     borderTop: { type: Boolean, default: true },
     borderBottom: { type: Boolean, default: true },
     borderLeft: { type: Boolean, default: true },

packages/runtime/src/paint/paint.ts

@@ -354,12 +354,16 @@ function drawBorder(
   const right = props["borderRight"] !== false;
 
   const borderColor = props["borderColor"] as string | undefined;
-  const dimAll = !!props["borderDimColor"];
+  // Keep the raw (non-coerced) general dim value so per-edge overrides work correctly.
+  const generalDim = props["borderDimColor"] as boolean | undefined;
 
   function colorizeEdge(s: string, edge: "top" | "bottom" | "left" | "right"): string {
     const capEdge = edge.charAt(0).toUpperCase() + edge.slice(1);
     const edgeColor = (props[`border${capEdge}Color`] as string | undefined) ?? borderColor;
-    const edgeDim = (props[`border${capEdge}DimColor`] as boolean | undefined) || dimAll;
+    // Use nullish coalescing (not ||) so an explicit per-edge `false` wins over
+    // generalDim — only `undefined` falls back to the general value.
+    // Mirrors Ink render-border.ts:54: `borderTopDimColor ?? borderDimColor`.
+    const edgeDim = (props[`border${capEdge}DimColor`] as boolean | undefined) ?? generalDim;
     // Ink parity (render-border.ts:44-52): an edge's background comes only from the
     // per-edge or general border background — never from the Box's own backgroundColor.
     const edgeBg =