Polish: session names take 900 weight serif-off; floating controls match graph chrome

- .font-title now requests font-weight: 900 — with the serif toggle OFF,
  the prose font is a VARIABLE font and was rendering titles at 400, a
  whisper next to CMU's bold-only face; 900 lands directly on Source
  Sans 3 and CMU's single 700 face snaps to nearest, unchanged. Same
  rendering with serif on, real weight with it off.
- The model + thinking pills match the graph view's floating top-right
  chrome (import notes / gear / coverage): border bg-card/85 shadow-lg
  backdrop-blur — the graph no longer bleeds through the pills.
- The dictate button gets the same blurring at lower opacity
  (bg-card/50 backdrop-blur), staying quieter than the model pills.

Gates: tsc clean, 866/866, lint 0, build ok. Live-verified: pills/dictate
computed styles byte-identical to the reference chrome (bg .85/.5 alpha +
blur(8px) + same shadow stack); title requests 900 in both serif states.

app/globals.css

@@ -178,6 +178,16 @@ body {
 	line-height: var(--lh-prose-leading);
 }
 
+/* Session-name weight (owner, fix wave round 3): with the serif toggle
+   OFF, --font-title resolves to the prose font — Source Sans 3 is loaded
+   as a VARIABLE font, and without an explicit weight the titles render at
+   400, a whisper next to CMU's bold-only face. Request 900: the variable
+   font takes it, and CMU (a single 700 face) snaps to its nearest
+   available weight — the same rendering it already had. */
+.font-title {
+	font-weight: 900;
+}
+
 .lh-prose :where(strong, b) {
 	color: var(--lh-ink-strong);
 	font-weight: 700;