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/question-dock.tsx

@@ -387,7 +387,7 @@ function QuestionDockForm({
 										setSel((prev) => (prev.otherSelected ? prev : toggleOther(selectMode, prev)));
 									}}
 									placeholder="Type your own answer…"
-									className="font-prose w-full min-w-0 flex-1 bg-transparent text-sm outline-none placeholder:text-muted-foreground"
+									className="lh-prose w-full min-w-0 flex-1 bg-transparent outline-none placeholder:text-muted-foreground"
 									onClick={(e) => e.stopPropagation()}
 								/>
 							</div>
@@ -429,7 +429,7 @@ function QuestionDockForm({
 							}}
 							placeholder="Type your answer…"
 							rows={1}
-							className="field-sizing-content font-prose max-h-48 min-h-10 w-full 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 w-full resize-none bg-transparent px-2.5 py-2 outline-none placeholder:text-muted-foreground"
 						/>
 					) : (
 						<textarea
@@ -446,7 +446,7 @@ function QuestionDockForm({
 							placeholder="Why this answer? What are you unsure about? Say as much as you like — the teacher reads all of this."
 							rows={1}
 							className={cn(
-								"field-sizing-content font-prose max-h-48 w-full resize-none bg-transparent px-2.5 py-2 text-sm outline-none placeholder:text-muted-foreground/70",
+								"field-sizing-content lh-prose max-h-48 w-full resize-none bg-transparent px-2.5 py-2 outline-none placeholder:text-muted-foreground/70",
 								// Phase-scaled prominence: teaching invites depth,
 								// probing stays quick.
 								phase === "teach" ? "min-h-[4.5rem]" : "min-h-10",