feat: show session name in statusline (#155)

* feat: show session name in statusline

Reads the session slug (auto-generated) and custom title (set via
/rename) from the transcript JSONL and displays it in dim text after
the project/git info on both expanded and compact layouts.

Custom title takes priority over auto-generated slug when both exist.

* test: add session name coverage and harden integration spawn

---------

Co-authored-by: Jarrod Watts <jarrod@cubelabs.xyz>

src/render/lines/project.ts

@@ -1,6 +1,6 @@
 import type { RenderContext } from '../../types.js';
 import { getModelName, getProviderLabel } from '../../stdin.js';
-import { cyan, magenta, yellow, red } from '../colors.js';
+import { cyan, dim, magenta, yellow, red } from '../colors.js';
 
 export function renderProjectLine(ctx: RenderContext): string | null {
   const display = ctx.config?.display;
@@ -60,6 +60,10 @@ export function renderProjectLine(ctx: RenderContext): string | null {
     parts.push(`${yellow(projectPath)}${gitPart}`);
   }
 
+  if (ctx.transcript.sessionName) {
+    parts.push(dim(ctx.transcript.sessionName));
+  }
+
   if (parts.length === 0) {
     return null;
   }

src/render/session-line.ts

@@ -100,6 +100,11 @@ export function renderSessionLine(ctx: RenderContext): string {
     parts.push(`${yellow(projectPath)}${gitPart}`);
   }
 
+  // Session name (custom title from /rename, or auto-generated slug)
+  if (ctx.transcript.sessionName) {
+    parts.push(dim(ctx.transcript.sessionName));
+  }
+
   // Config counts (respects environmentThreshold)
   if (display?.showConfigCounts !== false) {
     const totalCounts = ctx.claudeMdCount + ctx.rulesCount + ctx.mcpCount + ctx.hooksCount;

src/transcript.ts

@@ -4,6 +4,9 @@ import type { TranscriptData, ToolEntry, AgentEntry, TodoItem } from './types.js
 
 interface TranscriptLine {
   timestamp?: string;
+  type?: string;
+  slug?: string;
+  customTitle?: string;
   message?: {
     content?: ContentBlock[];
   };
@@ -33,6 +36,8 @@ export async function parseTranscript(transcriptPath: string): Promise<Transcrip
   const agentMap = new Map<string, AgentEntry>();
   let latestTodos: TodoItem[] = [];
   const taskIdToIndex = new Map<string, number>();
+  let latestSlug: string | undefined;
+  let customTitle: string | undefined;
 
   try {
     const fileStream = fs.createReadStream(transcriptPath);
@@ -46,6 +51,11 @@ export async function parseTranscript(transcriptPath: string): Promise<Transcrip
 
       try {
         const entry = JSON.parse(line) as TranscriptLine;
+        if (entry.type === 'custom-title' && typeof entry.customTitle === 'string') {
+          customTitle = entry.customTitle;
+        } else if (typeof entry.slug === 'string') {
+          latestSlug = entry.slug;
+        }
         processEntry(entry, toolMap, agentMap, taskIdToIndex, latestTodos, result);
       } catch {
         // Skip malformed lines
@@ -58,6 +68,7 @@ export async function parseTranscript(transcriptPath: string): Promise<Transcrip
   result.tools = Array.from(toolMap.values()).slice(-20);
   result.agents = Array.from(agentMap.values()).slice(-10);
   result.todos = latestTodos;
+  result.sessionName = customTitle ?? latestSlug;
 
   return result;
 }

src/types.ts

@@ -72,6 +72,7 @@ export interface TranscriptData {
   agents: AgentEntry[];
   todos: TodoItem[];
   sessionStart?: Date;
+  sessionName?: string;
 }
 
 export interface RenderContext {