Minimal-color round 1 (owner): phase color retired — the braille spinner is the one working indicator

Nothing exists purely for decoration: phase color-coding is retired
app-wide (phases only advance — every session ends Teaching — so
phase-as-signal was decoration with a one-time function), and what
state genuinely deserved — 'a turn is in flight' — is now carried by
MOTION alone, in the terminal's own glyph language.

- BrailleSpinner (components/braille-spinner.tsx): the canonical
  cli-spinner sequence (⠋⠙⠹⠸⠼⠴⠦⠧⠇⠏) as exact dot bitmaps in a 2×4
  braille cell, 80ms/frame (800ms cycle). Pure CSS: one shared keyframes,
  frames staggered via animation-delay; no JS timer, no re-render per
  frame — cheaper than the old breathing dot. Static contexts (SSR,
  prefers-reduced-motion) show frame 0 — a legible glyph, not a blank.
- Sidebar rows: spinner ONLY while a teach turn is in flight; idle and
  question-pending render NOTHING (a resting state has no scan value —
  the meta line's 'Waiting for your answer' text carries it). The
  three-state phase dot (pulse/solid/hollow) and PHASE_FILL/RING maps
  are gone.
- Top bar PhaseChip: label-only pill; the old dot slot becomes the
  spinner's home while a turn is in flight (busy prop wired from
  ChatView's busy = localStream || turnInFlight). Transcript
  PhaseDividers drop phase colors for monochrome rules + labels.
- API narrowing (app/api/chats/route.ts + ChatListItem contract):
  busy = isTurnRunning ONLY — background jobs no longer count (the
  sidebar's Background agents section is their channel; a per-row
  spinner would double-signal them).
- globals.css: --phase-* tokens + lh-dot-breathe removed (dead after
  the sweep — no remaining users).

Live-verified: idle/pending rows render no indicator, /chat/new chip is
label-only, 10 CSSAnimations at 800ms with correct 80ms stagger, static
frame 0 under reduced motion. Gates: typecheck, lint, 470/470, build.

Lane crossings to flag at merge: app/api/chats/route.ts + the
ChatListItem contract comment (src/core) — the busy-semantics narrowing;
components/chat.tsx one-line busy prop.

app/globals.css

@@ -232,53 +232,44 @@ body {
 }
 
 /* ============================================================
- * Session status — phase colors + status dots
- * (picker strips, header chip, transcript dividers: one language)
+ * Session status — the braille spinner (the one working indicator)
  * ============================================================ */
 
-/* Phase colors: blue = probing, violet = planning, green = teaching.
-   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);
-}
+/* (owner, minimal-color round) Phase color-coding is RETIRED: phases only
+   advance (every session ends in Teaching), so phase-as-signal was
+   decoration; the --phase-* tokens and every phase-dot state are gone.
+   What state deserved — "a turn is in flight" — is carried by MOTION
+   alone: the terminal braille spinner (components/braille-spinner.tsx),
+   monochrome, existing only while true. */
 
-.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);
-}
-
-@theme inline {
-	--color-phase-probe: var(--phase-probe);
-	--color-phase-plan: var(--phase-plan);
-	--color-phase-teach: var(--phase-teach);
-}
-
-/* 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 {
+/* One keyframes, all ten frames: each frame <g> holds opacity 1 for its
+   10% slice of the 800ms cycle and 0 elsewhere; frames stagger via
+   positive animation-delay (frame k starts at k×80ms). Static contexts
+   (SSR, reduced motion) show frame 0 — see the base rules below. */
+@keyframes braille-frame {
 	0%,
-	100% {
-		opacity: 0.35;
-		transform: scale(0.75);
+	10% {
+		opacity: 1;
 	}
 
-	50% {
-		opacity: 1;
-		transform: scale(1);
+	10.001%,
+	100% {
+		opacity: 0;
 	}
 }
 
-.lh-dot-breathe {
-	animation: lh-dot-breathe 1.4s ease-in-out infinite;
+.braille-frame {
+	animation: braille-frame 800ms linear infinite;
+	opacity: 0;
+}
+
+/* Static fallback: frame 0 (⠋) is the glyph a non-animated context shows. */
+.braille-frame[data-frame="0"] {
+	opacity: 1;
 }
 
 @media (prefers-reduced-motion: reduce) {
-	.lh-dot-breathe {
+	.braille-frame {
 		animation: none;
 	}
 }