feat(insights): render plain lists and bold in the AI prose surfaces

The prose renderer knew only blank-line paragraphs, so a reply that
enumerated options read as dash-prefixed text lines and a bold marker
surfaced as literal asterisks. ProseBlocks now groups consecutive
"- " lines into a real list and renders **bold** spans as strong
text — pure string splitting over the trusted string, fail-closed on
anything unclosed or unknown, still no markdown library. The Coach
streaming renderer settles completed paragraphs through the same
block renderer.

src/components/insights/__tests__/prose-blocks.test.tsx

@@ -84,6 +84,32 @@ describe("ProseBlocks", () => {
     expect(html).toContain("metric:WEIGHT");
     expect(html).not.toContain('data-slot="inline-learn-link"');
   });
+
+  it("groups consecutive '- ' lines into a real <ul> and strips the markers", () => {
+    const html = render(
+      <ProseBlocks
+        text={
+          "Two options stand out:\n- walk after lunch\n- an earlier bedtime\n\nBoth are low effort."
+        }
+      />,
+    );
+    expect((html.match(/<ul\b/g) ?? []).length).toBe(1);
+    expect((html.match(/<li\b/g) ?? []).length).toBe(2);
+    expect(html).toContain("walk after lunch");
+    expect(html).not.toContain("- walk");
+    // The intro line and the trailing paragraph stay real <p> blocks.
+    expect((html.match(/<p\b/g) ?? []).length).toBe(2);
+  });
+
+  it("renders a **bold** span as <strong> and leaves unclosed markers literal", () => {
+    const html = render(
+      <ProseBlocks
+        text={"The **key takeaway** stands.\n\nA stray ** stays literal."}
+      />,
+    );
+    expect(html).toContain("<strong>key takeaway</strong>");
+    expect(html).toContain("A stray ** stays literal.");
+  });
 });
 
 describe("StreamedProse", () => {

src/components/insights/coach-panel/streamed-prose.tsx

@@ -6,7 +6,7 @@ import { cn } from "@/lib/utils";
 import { stripChartTokens } from "@/lib/insights/chart-tokens";
 import {
   ProseBlocks,
-  ParagraphText,
+  ProseBlock,
   splitParagraphs,
   PROSE_PARAGRAPH_CLASS,
 } from "@/components/insights/prose-blocks";
@@ -96,13 +96,11 @@ export function StreamedProse({ content, streaming }: StreamedProseProps) {
 
   return (
     <>
-      {/* Completed paragraphs settle immediately — plain text + linkifier,
-          identical to the non-streaming render so nothing reflows when the
-          turn finishes. */}
+      {/* Completed paragraphs settle immediately — plain text + linkifier
+          (and real list markup for `- ` runs), identical to the
+          non-streaming render so nothing reflows when the turn finishes. */}
       {settled.map((p, i) => (
-        <p key={i} className={cn(PROSE_PARAGRAPH_CLASS)}>
-          <ParagraphText text={p} strip />
-        </p>
+        <ProseBlock key={i} text={p} strip />
       ))}
       {/* The growing tail paragraph: word-by-word fade. No linkify here —
           a half-arrived URL must not flicker into a link mid-stream; it

src/components/insights/prose-blocks.tsx

@@ -102,13 +102,55 @@ function linkifyLearnLinks(line: string): ReactNode {
   return <>{nodes}</>;
 }
 
+/**
+ * `**bold**` span matcher. The ONLY inline emphasis the formatting contract
+ * allows the models; anything else (headings, underscores, backticks) stays
+ * literal text. No `*` or `\n` inside the span, so an unclosed `**` or a
+ * stray asterisk falls through verbatim — fail-closed, never swallowed.
+ */
+const BOLD_SPAN_RE = /\*\*([^*\n]+)\*\*/g;
+
+/**
+ * Render one line's inline content: closed-set `**bold**` spans become
+ * `<strong>`, and each plain/bold fragment runs through the catalog-
+ * whitelisted Learn linkifier. Pure `matchAll` + slicing over the trusted
+ * string — no parser, no markup passthrough.
+ */
+function renderInline(line: string, linkify: boolean): ReactNode {
+  const linkified = (s: string) => (linkify ? linkifyLearnLinks(s) : s);
+  if (!line.includes("**")) return linkified(line);
+
+  const nodes: ReactNode[] = [];
+  let lastIndex = 0;
+  let key = 0;
+  for (const match of line.matchAll(BOLD_SPAN_RE)) {
+    const start = match.index ?? 0;
+    if (start > lastIndex)
+      nodes.push(
+        <Fragment key={`t-${key++}`}>
+          {linkified(line.slice(lastIndex, start))}
+        </Fragment>,
+      );
+    nodes.push(<strong key={`b-${key++}`}>{linkified(match[1])}</strong>);
+    lastIndex = start + match[0].length;
+  }
+  if (nodes.length === 0) return linkified(line);
+  if (lastIndex < line.length)
+    nodes.push(
+      <Fragment key={`t-${key++}`}>
+        {linkified(line.slice(lastIndex))}
+      </Fragment>,
+    );
+  return <>{nodes}</>;
+}
+
 /**
  * Render one paragraph's inner text: each single `\n` becomes a `<br/>`, each
- * line is (optionally) chart-token-stripped, then run through the
- * catalog-whitelisted Learn linkifier. Stripping per LINE preserves the
- * `\n` breaks that a whole-string strip would collapse. Exported so the
- * Coach streaming renderer can settle completed paragraphs with the same
- * markup the non-streaming path produces.
+ * line is (optionally) chart-token-stripped, then run through the closed-set
+ * inline renderer (`**bold**` + the catalog-whitelisted Learn linkifier).
+ * Stripping per LINE preserves the `\n` breaks that a whole-string strip
+ * would collapse. Exported so the Coach streaming renderer can settle
+ * completed paragraphs with the same markup the non-streaming path produces.
  */
 export function ParagraphText({
   text,
@@ -127,7 +169,7 @@ export function ParagraphText({
         return (
           <Fragment key={i}>
             {i > 0 && <br />}
-            {linkify ? linkifyLearnLinks(cleaned) : cleaned}
+            {renderInline(cleaned, linkify)}
           </Fragment>
         );
       })}
@@ -135,6 +177,66 @@ export function ParagraphText({
   );
 }
 
+/** `- ` / `– ` / `• ` list-item marker (leading whitespace tolerated). */
+const BULLET_LINE_RE = /^\s*[-–•]\s+/;
+
+/**
+ * Render ONE blank-line-delimited block: consecutive `- ` lines group into a
+ * real `<ul>` (marker stripped, one `<li>` per line), the remaining line runs
+ * render as `<p>` with `<br/>` joins — so a model reply that enumerates
+ * ("- option one\n- option two") reads as a list instead of dash-prefixed
+ * text lines. Same pure line-splitting as everything else here: no parser,
+ * no markup passthrough. Exported for the Coach streaming renderer.
+ */
+export function ProseBlock({
+  text,
+  strip = false,
+  linkify = true,
+  paragraphClassName,
+}: {
+  text: string;
+  strip?: boolean;
+  linkify?: boolean;
+  paragraphClassName?: string;
+}) {
+  const blockClass = cn(paragraphClassName ?? PROSE_PARAGRAPH_CLASS);
+  const lines = text.split("\n");
+  const runs: Array<{ bullets: boolean; lines: string[] }> = [];
+  for (const line of lines) {
+    const bullets = BULLET_LINE_RE.test(line);
+    const last = runs[runs.length - 1];
+    if (last && last.bullets === bullets) last.lines.push(line);
+    else runs.push({ bullets, lines: [line] });
+  }
+  return (
+    <>
+      {runs.map((run, i) =>
+        run.bullets ? (
+          <ul key={i} className={cn(blockClass, "list-disc space-y-1 pl-5")}>
+            {run.lines.map((line, j) => (
+              <li key={j}>
+                <ParagraphText
+                  text={line.replace(BULLET_LINE_RE, "")}
+                  strip={strip}
+                  linkify={linkify}
+                />
+              </li>
+            ))}
+          </ul>
+        ) : (
+          <p key={i} className={blockClass}>
+            <ParagraphText
+              text={run.lines.join("\n")}
+              strip={strip}
+              linkify={linkify}
+            />
+          </p>
+        ),
+      )}
+    </>
+  );
+}
+
 export interface ProseBlocksProps {
   /** Trusted-as-text prose (model output already verified server-side). */
   text: string;
@@ -166,9 +268,13 @@ export function ProseBlocks({
   return (
     <>
       {paras.map((p, i) => (
-        <p key={i} className={cn(paragraphClassName ?? PROSE_PARAGRAPH_CLASS)}>
-          <ParagraphText text={p} strip={strip} linkify={linkify} />
-        </p>
+        <ProseBlock
+          key={i}
+          text={p}
+          strip={strip}
+          linkify={linkify}
+          paragraphClassName={paragraphClassName}
+        />
       ))}
     </>
   );