fix(core,cli): parent-relative figma child geometry; groups stop rejecting subcommand flags

Both found running the brand-loop guide end-to-end against the Simple
Design System:

- nodeToHtml subtracted the ROOT origin from every node's absolute bounds,
  but CSS absolute positioning resolves against the nearest positioned
  ancestor — every nesting level re-added its ancestors' offsets, drifting
  nested content down-right and pushing deep children off-frame (hero
  buttons invisible, pricing grid collapsed to one card). Children now
  subtract their PARENT's box; regression test with a two-level tree.

- trackCommandFailures asserted unknown flags against the command group's
  own (flagless) arg table even when the group was delegating to a
  subcommand, so `figma component <ref> --name x` imported and THEN threw
  "Unknown flag: --name". The assertion is now skipped when the first
  positional names a subcommand; leaf and non-delegating behavior is
  unchanged and covered by tests.

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

packages/core/src/figma/nodeToHtml.ts

@@ -186,7 +186,7 @@ function unresolvedAttr(node: FigmaNodeDocument, ctx: RenderContext): string {
   return ` data-figma-unresolved="${escapeHtml(props.join(" "))}"`;
 }
 
-function geometryCss(node: FigmaNodeDocument, ctx: RenderContext, isRoot: boolean): string[] {
+function geometryCss(node: FigmaNodeDocument, parentBox: Box, isRoot: boolean): string[] {
   const box = boxOf(node);
   const styles: string[] = [];
   if (!box) return styles;
@@ -197,10 +197,14 @@ function geometryCss(node: FigmaNodeDocument, ctx: RenderContext, isRoot: boolea
       `height: ${round(box.height)}px`,
     );
   } else {
+    // CSS absolute positioning is relative to the nearest positioned
+    // ancestor — the PARENT's box, not the root origin. Subtracting the root
+    // for every depth double-offsets nested children (each level re-adds its
+    // ancestors' offsets), drifting content down-right and off-frame.
     styles.push(
       "position: absolute",
-      `left: ${round(box.x - ctx.origin.x)}px`,
-      `top: ${round(box.y - ctx.origin.y)}px`,
+      `left: ${round(box.x - parentBox.x)}px`,
+      `top: ${round(box.y - parentBox.y)}px`,
       `width: ${round(box.width)}px`,
       `height: ${round(box.height)}px`,
     );
@@ -243,10 +247,15 @@ function decorationCss(node: FigmaNodeDocument, ctx: RenderContext): string[] {
 // instead of a RangeError; real figma frames are nowhere near this deep.
 const MAX_DEPTH = 500;
 
-function renderChildren(node: FigmaNodeDocument, ctx: RenderContext, depth: number): string {
+function renderChildren(
+  node: FigmaNodeDocument,
+  ctx: RenderContext,
+  depth: number,
+  parentBox: Box,
+): string {
   const childHtml: string[] = [];
   for (const child of childDocuments(node)) {
-    const rendered = renderNodeHtml(child, ctx, false, depth + 1);
+    const rendered = renderNodeHtml(child, ctx, false, depth + 1, parentBox);
     if (rendered.length > 0) childHtml.push(rendered);
   }
   return childHtml.length > 0 ? `\n${childHtml.join("\n")}\n` : "";
@@ -257,11 +266,12 @@ function renderNodeHtml(
   ctx: RenderContext,
   isRoot: boolean,
   depth = 0,
+  parentBox: Box = ctx.origin,
 ): string {
   if (node.visible === false || depth > MAX_DEPTH) return "";
   const slug = uniqueSlug(ctx, node.name);
   const style = escapeHtml(
-    [...geometryCss(node, ctx, isRoot), ...decorationCss(node, ctx)].join("; "),
+    [...geometryCss(node, parentBox, isRoot), ...decorationCss(node, ctx)].join("; "),
   );
   // data-hf-snippet marks the file as a mountable fragment, not a standalone
   // composition — the project linter skips composition-root rules for it.
@@ -278,7 +288,7 @@ function renderNodeHtml(
     return `<div ${idAttrs} style="${style}">${text}</div>`;
   }
 
-  return `<div ${idAttrs} style="${style}">${renderChildren(node, ctx, depth)}</div>`;
+  return `<div ${idAttrs} style="${style}">${renderChildren(node, ctx, depth, boxOf(node) ?? parentBox)}</div>`;
 }
 
 export interface NodeToHtmlOptions {