fix: CSP null for tool windows + tauri://error diagnostic listeners

Tool windows open/close immediately — diagnostic build:
- CSP set to null to eliminate it as a variable. The CSP was blocking
  IPC initialization in child WebviewWindows on macOS WKWebView.
- Added tauri://error listeners to ALL WebviewWindow creations (tool,
  help, editor, detach). If window creation fails on the Rust side,
  an alert will show the error instead of silently closing.
- If tool windows work with csp:null, we know the CSP was the cause
  and can craft a macOS-compatible policy. If they still fail, the
  error alert will reveal the actual Rust-side error.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src-tauri/tauri.conf.json

@@ -23,7 +23,7 @@
       }
     ],
     "security": {
-      "csp": "default-src 'self' 'unsafe-inline' asset: https://asset.localhost; img-src 'self' asset: https://asset.localhost data: blob:; connect-src ipc: http://ipc.localhost https://ipc.localhost"
+      "csp": null
     },
     "withGlobalTauri": false
   },

src/components/session/TabBar.vue

@@ -135,7 +135,7 @@ async function detachTab(): Promise<void> {
   // Open a new Tauri window for this session
   const { WebviewWindow } = await import("@tauri-apps/api/webviewWindow");
   const label = `detached-${session.id.substring(0, 8)}-${Date.now()}`;
-  new WebviewWindow(label, {
+  const wv = new WebviewWindow(label, {
     title: `${session.name} — Wraith`,
     width: 900,
     height: 600,
@@ -143,6 +143,7 @@ async function detachTab(): Promise<void> {
     center: true,
     url: `index.html#/detached-session?sessionId=${session.id}&name=${encodeURIComponent(session.name)}&protocol=${session.protocol}`,
   });
+  wv.once("tauri://error", (e) => { console.error("Detach window error:", e); });
 }
 
 function closeMenuTab(): void {

src/layouts/MainLayout.vue

@@ -369,7 +369,7 @@ async function handleHelpAction(page: string): Promise<void> {
   showHelpMenu.value = false;
   const { WebviewWindow } = await import("@tauri-apps/api/webviewWindow");
   const label = `help-${page}-${Date.now()}`;
-  new WebviewWindow(label, {
+  const wv = new WebviewWindow(label, {
     title: `Wraith — Help`,
     width: 750,
     height: 600,
@@ -377,6 +377,7 @@ async function handleHelpAction(page: string): Promise<void> {
     center: true,
     url: `index.html#/tool/help?page=${page}`,
   });
+  wv.once("tauri://error", (e) => { console.error("Help window error:", e); alert("Window error: " + JSON.stringify(e.payload)); });
 }
 
 async function handleToolAction(tool: string): Promise<void> {
@@ -414,7 +415,7 @@ async function handleToolAction(tool: string): Promise<void> {
 
   // Open tool in a new Tauri window
   const label = `tool-${tool}-${Date.now()}`;
-  new WebviewWindow(label, {
+  const wv = new WebviewWindow(label, {
     title: `Wraith — ${config.title}`,
     width: config.width,
     height: config.height,
@@ -422,6 +423,7 @@ async function handleToolAction(tool: string): Promise<void> {
     center: true,
     url: `index.html#/tool/${tool}?sessionId=${sessionId}`,
   });
+  wv.once("tauri://error", (e) => { console.error("Tool window error:", e); alert("Window error: " + JSON.stringify(e.payload)); });
 }
 
 async function handleFileMenuAction(action: string): Promise<void> {
@@ -446,7 +448,7 @@ async function handleOpenFile(entry: FileEntry): Promise<void> {
     const label = `editor-${Date.now()}`;
     const sessionId = activeSessionId.value;
 
-    new WebviewWindow(label, {
+    const wv = new WebviewWindow(label, {
       title: `${fileName} — Wraith Editor`,
       width: 800,
       height: 600,
@@ -454,6 +456,7 @@ async function handleOpenFile(entry: FileEntry): Promise<void> {
       center: true,
       url: `index.html#/tool/editor?sessionId=${sessionId}&path=${encodeURIComponent(entry.path)}`,
     });
+    wv.once("tauri://error", (e) => { console.error("Editor window error:", e); alert("Window error: " + JSON.stringify(e.payload)); });
   } catch (err) { console.error("Failed to open editor:", err); }
 }