Wave-5 refinement round 3 (owner): SVG answer marks + uniform input sizes

- ✓/✗ in the answered card: replaced literal glyphs with lucide CheckIcon/
  XIcon (strokeWidth 2.5) inside a fixed size-4 flex box — text elements
  never carried the right size/vertical alignment, vectors do. Test pins
  updated (lucide-check/lucide-x classes).
- All user-typed INPUT text now matches markdown output: lh-prose class
  replaces the earlier font-prose (family-only) band-aid on the composer,
  question-dock text/thinking/Other fields, home topic input, model search
  box, and answered-card 'your thinking'/free-text records. lh-prose sets
  family+size (16.5px) so placeholders inherit correctly.

components/composer.tsx

@@ -59,7 +59,7 @@ export function Composer({
 				placeholder="Ask, answer, or steer the lesson…"
 				autoFocus={autoFocus}
 				rows={1}
-				className="field-sizing-content font-prose max-h-48 min-h-10 flex-1 resize-none bg-transparent px-2.5 py-2 text-sm outline-none placeholder:text-muted-foreground"
+				className="field-sizing-content lh-prose max-h-48 min-h-10 flex-1 resize-none bg-transparent px-2.5 py-2 outline-none placeholder:text-muted-foreground"
 			/>
 			{verdict && !busy ? (
 				// The plan verdict (docs/probe-teach-split.md §4): accept