feat: message-per-row transcript, session resume, drop the composer (#4)

src/lib/markdown.ts

@@ -1,80 +1,72 @@
-import type { ChatTurn } from "./types";
+import type { ChatTurn, ThreadMessage } from "./types";
 
 /**
- * Renders a turn as markdown for the detail panel.
+ * Markdown rendering for the detail panel.
  *
- * Kept as a pure function so the transcript layout can be tested without
- * mounting a component, and so the same renderer can serve both a finished
- * turn and one that is still streaming.
+ * Kept as pure functions so the transcript layout can be tested without
+ * mounting a component.
+ *
+ * The user/assistant distinction is carried by markdown itself: user messages
+ * render as blockquotes, which the renderer draws in a dimmed italic style,
+ * while answers render as normal body text. That mirrors how the list rows
+ * dim the question and brighten the answer, so the two panes agree.
  */
 
 export const STREAMING_CURSOR = "▍";
 
-export interface TurnMarkdownInput {
-  prompt: string;
-  response: string;
-  thinking?: string;
-  toolCalls?: ChatTurn["toolCalls"];
-  error?: string;
-  model?: string;
-  createdAt?: number;
-  isStreaming?: boolean;
-}
-
-/** Prefixes every line so a multi-line prompt renders as one continuous quote block. */
-function quote(text: string): string {
+/** Prefixes every line so a multi-line message stays one continuous quote block. */
+export function quote(text: string): string {
   return text
     .split("\n")
     .map((line) => `> ${line}`.trimEnd())
     .join("\n");
 }
 
-export function buildTurnMarkdown(input: TurnMarkdownInput): string {
-  const sections: string[] = [];
+/** A short one-line preview of a message, for a list row. */
+export function previewText(text: string, max: number): string {
+  const collapsed = text.replace(/\s+/g, " ").trim();
+  if (collapsed.length <= max) return collapsed;
+  return `${collapsed.slice(0, Math.max(0, max - 1)).trimEnd()}…`;
+}
 
-  sections.push(quote(input.prompt));
-  sections.push("");
-
-  const body = input.response.trim() || (input.isStreaming ? "_Thinking…_" : "_No response._");
-  sections.push(input.isStreaming ? `${body} ${STREAMING_CURSOR}` : body);
-
-  if (input.error) {
-    sections.push("", `**Error** — ${input.error}`);
+function renderMessage(message: ThreadMessage): string {
+  if (message.role === "user") {
+    return `**You**\n\n${quote(message.text)}`;
   }
 
-  const toolCalls = input.toolCalls ?? [];
-  if (toolCalls.length > 0) {
-    const lines = toolCalls.map((call) => `- \`${call.name}\`${call.isError ? " — failed" : ""}`);
+  const body = message.text.trim() || (message.isStreaming ? "_Thinking…_" : "_No response._");
+  const sections = ["**Lam**", "", message.isStreaming ? `${body} ${STREAMING_CURSOR}` : body];
+
+  if (message.error) {
+    sections.push("", `**Error** — ${message.error}`);
+  }
+
+  if (message.toolCalls.length > 0) {
+    const lines = message.toolCalls.map(
+      (call) => `- \`${call.name}\`${call.isError ? " — failed" : ""}`,
+    );
     sections.push("", "**Tools used**", ...lines);
   }
 
-  if (input.thinking && input.thinking.trim().length > 0) {
-    sections.push("", "---", "", "**Reasoning**", "", quote(input.thinking.trim()));
-  }
-
-  const footer: string[] = [];
-  if (input.model) footer.push(`\`${input.model}\``);
-  if (input.createdAt) footer.push(new Date(input.createdAt).toLocaleString());
-
-  if (footer.length > 0) {
-    sections.push("", "---", "", footer.join(" · "));
+  if (message.thinking.trim().length > 0) {
+    sections.push("", "_Reasoning_", "", quote(message.thinking.trim()));
   }
 
   return sections.join("\n");
 }
 
-/** The placeholder shown while the first tokens are still in flight. */
-export function pendingMarkdown(prompt: string, status?: string): string {
-  const lines = [quote(prompt), ""];
-  lines.push(status ? `_${status}…_` : "_Thinking…_");
-  return lines.join("\n");
-}
-
-/** A short one-line preview of an answer, for a collapsed row. */
-export function previewText(text: string, max: number): string {
-  const collapsed = text.replace(/\s+/g, " ").trim();
-  if (collapsed.length <= max) return collapsed;
-  return `${collapsed.slice(0, Math.max(0, max - 1)).trimEnd()}…`;
+/**
+ * Renders the whole conversation.
+ *
+ * The detail panel shows the full thread rather than just the selected message
+ * on purpose. Vicinae's list resets its selection to the first row whenever the
+ * model changes, and streaming changes it on every flush, so the selected row
+ * is not something the extension can rely on staying put while an answer
+ * arrives. Showing the thread means the live answer is always on screen.
+ */
+export function buildThreadMarkdown(messages: ThreadMessage[]): string {
+  if (messages.length === 0) return "";
+  return messages.map(renderMessage).join("\n\n---\n\n");
 }
 
 /**