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.

tests/render-phase-divider.test.tsx

@@ -1,8 +1,10 @@
 /**
- * Phase presentation render tests — the in-session face of the picker's
- * color strips (components/phase-divider.tsx): the header chip and the
- * dotted transcript boundary rules. Same tsx classic-JSX shim as
- * render-cards.test.tsx. (Replaces the old part-level PlanDivider tests.)
+ * Phase presentation render tests — the in-session face (components/
+ * phase-divider.tsx), monochrome since the minimal-color round: the header
+ * chip (label + the braille spinner in the old dot slot while a turn is in
+ * flight) and the dotted transcript boundary rules. Same tsx classic-JSX
+ * shim as render-cards.test.tsx. (Replaces the old part-level PlanDivider
+ * tests.)
  */
 import React from "react";
 (globalThis as Record<string, unknown>).React = React;
@@ -13,7 +15,7 @@ import { renderToStaticMarkup } from "react-dom/server";
 import { PhaseChip, PhaseDivider, planNodeCount } from "../components/phase-divider.tsx";
 
 describe("PhaseChip (header)", () => {
-	it("renders a phase-colored dot + the learner-facing label", () => {
+	it("renders the learner-facing label — no colored dot (phase color retired)", () => {
 		for (const [phase, label] of [
 			["probe", "Probing"],
 			["plan", "Planning"],
@@ -23,25 +25,40 @@ describe("PhaseChip (header)", () => {
 			assert.ok(html.includes('data-testid="phase-chip"'));
 			assert.ok(html.includes(`data-phase="${phase}"`));
 			assert.ok(html.includes(label), `${phase} label`);
-			assert.ok(html.includes(`bg-phase-${phase}`), `${phase} dot color`);
+			assert.ok(!html.includes("bg-phase-"), `${phase} dot color retired`);
+			assert.ok(!html.includes("rounded-full bg-"), "no dot of any color — label only");
 		}
 	});
+
+	it("busy: the old dot slot becomes the braille spinner (motion = turn in flight)", () => {
+		const html = renderToStaticMarkup(<PhaseChip phase="teach" busy />);
+		assert.ok(html.includes('data-testid="braille-spinner"'), "spinner in the chip");
+		assert.ok(html.includes("Teaching"), "label stays");
+		assert.ok((html.match(/class="braille-frame"/g) ?? []).length === 10, "all ten frames");
+	});
+
+	it("idle: no spinner — the chip is the label alone", () => {
+		const html = renderToStaticMarkup(<PhaseChip phase="teach" />);
+		assert.ok(!html.includes("braille-spinner"));
+	});
 });
 
 describe("PhaseDivider (transcript boundary)", () => {
-	it("the plan seam: dotted rules in the plan color + node count", () => {
+	it("the plan seam: monochrome dotted rules + node count", () => {
 		const html = renderToStaticMarkup(<PhaseDivider phase="plan" nodeCount={3} />);
 		assert.ok(html.includes('data-testid="phase-divider-plan"'));
 		assert.match(html, /Plan · 3 nodes/);
 		assert.ok(html.includes("border-dotted"), "dotted rule");
-		assert.ok(html.includes("border-phase-plan"), "plan-colored rule");
+		assert.ok(html.includes("border-border"), "monochrome rule");
+		assert.ok(!html.includes("border-phase-"), "phase-colored rules are retired");
 	});
 
-	it("the teach seam: dotted rules in the teach color, no count", () => {
+	it("the teach seam: monochrome rule, no count", () => {
 		const html = renderToStaticMarkup(<PhaseDivider phase="teach" />);
 		assert.ok(html.includes('data-testid="phase-divider-teach"'));
 		assert.match(html, /Teaching/);
-		assert.ok(html.includes("border-phase-teach"));
+		assert.ok(!html.includes("border-phase-"));
+		assert.ok(!html.includes("text-phase-"));
 		assert.ok(!html.includes("nodes"));
 	});