Session picker: one phase-colored dot, state via fill + motion

Redesign per review feedback: the colored phase strips were too busy —
removed. One small dot now carries two channels:

- COLOR = phase (sky/violet/emerald, same system as chip + dividers)
- FILL + MOTION = what's owed:
  - pulsing  = teacher is working (the only state that deserves motion)
  - solid    = a question awaits the learner's answer — the dominant
               resting state of real sessions, so deliberately calm
  - hollow   = idle, nothing owed

The amber attention channel is gone entirely (it would read as a
phantom fourth phase). The meta line now leads with the useful fact:
"Waiting for your answer · 5m ago" / "Teacher is working…" — the
message count only shows when idle. Ordering stays pure recency.

app/globals.css

@@ -164,48 +164,29 @@ body {
  * ============================================================ */
 
 /* Phase colors: blue = probing, violet = planning, green = teaching.
-   Tuned per theme (light needs darker, dark lighter). The attention color
-   (an answer the learner owes) is deliberately outside the phase system —
-   dots and strips are separate channels and must not read as one. */
+   Tuned per theme (light needs darker, dark lighter). These color the
+   session dots, header chip and transcript dividers — one language. */
 :root {
 	--phase-probe: oklch(0.55 0.17 253);
 	--phase-plan: oklch(0.54 0.19 300);
 	--phase-teach: oklch(0.55 0.14 160);
-	--attention: oklch(0.62 0.15 65);
 }
 
 .dark {
 	--phase-probe: oklch(0.72 0.13 250);
 	--phase-plan: oklch(0.72 0.14 300);
 	--phase-teach: oklch(0.74 0.12 160);
-	--attention: oklch(0.8 0.15 75);
 }
 
 @theme inline {
 	--color-phase-probe: var(--phase-probe);
 	--color-phase-plan: var(--phase-plan);
 	--color-phase-teach: var(--phase-teach);
-	--color-attention: var(--attention);
-}
-
-/* Status dots (session picker). Attention — a slow expanding ring, drawing
-   the eye to "your move". Working — a quiet breathing dot, opacity only,
-   never loud enough to compete with the attention ring. */
-@keyframes lh-dot-attention {
-	0% {
-		box-shadow: 0 0 0 0 color-mix(in oklab, var(--attention) 60%, transparent);
-	}
-
-	70%,
-	100% {
-		box-shadow: 0 0 0 5px transparent;
-	}
-}
-
-.lh-dot-attention {
-	animation: lh-dot-attention 1.6s ease-out infinite;
 }
 
+/* Session dot motion (picker): the ONLY animated state is "teacher is
+   working" — a quiet phase-colored breathing. Pending questions are the
+   dominant resting state and stay perfectly still (solid dot). */
 @keyframes lh-dot-breathe {
 	0%,
 	100% {
@@ -224,9 +205,7 @@ body {
 }
 
 @media (prefers-reduced-motion: reduce) {
-
-	.lh-dot-attention,
-		.lh-dot-breathe {
+	.lh-dot-breathe {
 		animation: none;
 	}
 }