🤖 feat: display init hook script path in banner for debugging

The init hook banner now shows the full path to the script being executed,
making it easier for users to debug initialization issues.

Changes:
- Added `hookPath` field to workspace-init DisplayedMessage type
- Updated StreamingMessageAggregator to capture and track hookPath from init-start events
- Enhanced InitMessage component to display hookPath below status message
- Styled hookPath with muted monospace font for clarity

The hookPath appears in smaller, muted text below the main status message,
helping users quickly identify which script is running and where to find it.

Output streaming already worked - init-output events were already being
accumulated and displayed in the InitHookLog component.

_Generated with `cmux`_

Author: ammar-agent

src/components/Messages/InitMessage.tsx

@@ -26,6 +26,13 @@ const InitHookHeader = styled.div`
   color: #ccc;
 `;
 
+const InitHookPath = styled.div`
+  font-size: 11px;
+  color: #888;
+  font-family: var(--font-monospace);
+  margin-top: 2px;
+`;
+
 const InitHookLog = styled.pre`
   margin: 0;
   max-height: 120px;
@@ -44,16 +51,19 @@ export const InitMessage = React.memo<InitMessageProps>(({ message, className })
     <InitHookBanner error={isError} className={className}>
       <InitHookHeader>
         <span>🔧</span>
-        {message.status === "running" ? (
-          <span>Running init hook...</span>
-        ) : message.status === "success" ? (
-          <span>✅ Init hook completed successfully</span>
-        ) : (
-          <span>
-            Init hook exited with code {message.exitCode}. Workspace is ready, but some setup
-            failed.
-          </span>
-        )}
+        <div>
+          {message.status === "running" ? (
+            <span>Running init hook...</span>
+          ) : message.status === "success" ? (
+            <span>✅ Init hook completed successfully</span>
+          ) : (
+            <span>
+              Init hook exited with code {message.exitCode}. Workspace is ready, but some setup
+              failed.
+            </span>
+          )}
+          <InitHookPath>{message.hookPath}</InitHookPath>
+        </div>
       </InitHookHeader>
       {message.lines.length > 0 && <InitHookLog>{message.lines.join("\n")}</InitHookLog>}
     </InitHookBanner>

src/types/message.ts

@@ -172,6 +172,7 @@ export type DisplayedMessage =
       id: string; // Display ID for UI/React keys
       historySequence: number; // Position in message stream (-1 for ephemeral, non-persisted events)
       status: "running" | "success" | "error";
+      hookPath: string; // Path to the init script being executed
       lines: string[]; // Accumulated output lines (stderr prefixed with "ERROR:")
       exitCode: number | null; // Final exit code (null while running)
       timestamp: number;

src/utils/messages/StreamingMessageAggregator.ts

@@ -54,6 +54,7 @@ export class StreamingMessageAggregator {
   // Workspace init hook state (ephemeral, not persisted to history)
   private initState: {
     status: "running" | "success" | "error";
+    hookPath: string;
     lines: string[];
     exitCode: number | null;
     timestamp: number;
@@ -508,6 +509,7 @@ export class StreamingMessageAggregator {
     if (isInitStart(data)) {
       this.initState = {
         status: "running",
+        hookPath: data.hookPath,
         lines: [],
         exitCode: null,
         timestamp: data.timestamp,
@@ -771,6 +773,7 @@ export class StreamingMessageAggregator {
           id: "workspace-init",
           historySequence: -1, // Appears before all history
           status: this.initState.status,
+          hookPath: this.initState.hookPath,
           lines: this.initState.lines,
           exitCode: this.initState.exitCode,
           timestamp: this.initState.timestamp,