Typography round 2 (owner): lh-input (caret at the font-metric floor) + 14px session titles

- lh-input: lh-prose's 1.5 reading leading made typing carets tower
  (~25px box on 16.5px text, ~2.1× the glyphs — the caret fills the line
  box in Chromium). Inputs are not paragraphs: 1.25 leading drops the
  caret to ~21px, the font-metric floor (as close to the glyphs as
  Chromium will draw). Swapped on every typing surface — composer
  (chat + home), the thinking field, answer + editable-Other inputs, the
  model search; rendered prose (message.tsx container, option
  descriptions, chat.tsx pre-wrap) keeps lh-prose 1.5. Same family and
  size as prose; only leading differs.
- Session titles: 14px (text-base) — Source Sans at 12.5px read as
  small as the 11px mono meta under them; the title now holds its rank.
  Live: title "Source Sans 3" 14px vs meta "JetBrains Mono" 11px, row
  52px; composer line box 20.625px (was 24.75px).

Gates: typecheck, lint, 469/469.

app/globals.css

@@ -164,6 +164,19 @@ body {
 	color: var(--lh-ink-italic);
 }
 
+/* lh-input (owner, typography round 2): lh-prose's 1.5 READING leading
+   makes typing carets tower over the glyphs — the caret fills the line
+   box (24.75px at 16.5px text, ~2.1× the glyph height). Inputs are not
+   paragraphs: a tighter 1.25 leading brings the caret to the font-metric
+   floor (~21px, as close to the glyphs as Chromium will draw it) while
+   wrapped lines in growing textareas still read fine. Rendered prose keeps
+   1.5 — the two share family and size, they differ only in leading. */
+.lh-input {
+	font-family: var(--font-prose);
+	font-size: var(--lh-prose-size);
+	line-height: 1.25;
+}
+
 /* Thin dark native scrollbar (app-wide): dark thumb, transparent track. */
 * {
 	scrollbar-width: thin;