Update logo, app icon, fix shutdown crash, add README

- Simplified logo: cosmic latte cup on brown background with turquoise
  liquid and sparkle stars
- Square app icon (.icns) for macOS dock
- Fix crash on window close: guard all IPC sends against destroyed window
- Include ws/chokidar/diff-match-patch in packaged app
- Add README with features and install instructions

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

3 files changed, 27 insertions, 24 deletions

diff --git a/src/main/index.ts b/src/main/index.ts
index b543b46..7fab07a 100644
--- a/src/main/index.ts
+++ b/src/main/index.ts
@@ -38,6 +38,13 @@ function createWindow(): void {
   }
 }
 
+/** Safely send IPC to renderer — no-op if window is gone */
+function sendToRenderer(channel: string, ...args: unknown[]) {
+  if (mainWindow && !mainWindow.isDestroyed()) {
+    mainWindow.webContents.send(channel, ...args)
+  }
+}
+
 ipcMain.handle('fs:readFile', async (_e, filePath: string) => {
   return readFile(filePath, 'utf-8')
 })
@@ -99,11 +106,11 @@ ipcMain.handle('pty:spawn', async (_e, cwd: string) => {
   })
 
   ptyInstance.onData((data) => {
-    mainWindow?.webContents.send('pty:data', data)
+    sendToRenderer('pty:data', data)
   })
 
   ptyInstance.onExit(() => {
-    mainWindow?.webContents.send('pty:exit')
+    sendToRenderer('pty:exit')
   })
 })
 
@@ -602,7 +609,7 @@ ipcMain.handle('ot:connect', async (_e, projectId: string) => {
 
     // Relay events to renderer
     overleafSock.on('connectionState', (state: string) => {
-      mainWindow?.webContents.send('ot:connectionState', state)
+      sendToRenderer('ot:connectionState', state)
     })
 
     // otUpdateApplied: server acknowledges our op (ack signal for OT client)
@@ -610,13 +617,13 @@ ipcMain.handle('ot:connect', async (_e, projectId: string) => {
       if (name === 'otUpdateApplied') {
         const update = args[0] as { doc?: string; v?: number } | undefined
         if (update?.doc) {
-          mainWindow?.webContents.send('ot:ack', { docId: update.doc })
+          sendToRenderer('ot:ack', { docId: update.doc })
         }
       }
     })
 
     overleafSock.on('docRejoined', (docId: string, result: JoinDocResult) => {
-      mainWindow?.webContents.send('ot:docRejoined', {
+      sendToRenderer('ot:docRejoined', {
         docId,
         content: result.docLines.join('\n'),
         version: result.version
@@ -626,11 +633,11 @@ ipcMain.handle('ot:connect', async (_e, projectId: string) => {
     // Relay collaborator cursor updates to renderer
     overleafSock.on('serverEvent', (name: string, args: unknown[]) => {
       if (name === 'clientTracking.clientUpdated') {
-        mainWindow?.webContents.send('cursor:remoteUpdate', args[0])
+        sendToRenderer('cursor:remoteUpdate', args[0])
       } else if (name === 'clientTracking.clientDisconnected') {
-        mainWindow?.webContents.send('cursor:remoteDisconnected', args[0])
+        sendToRenderer('cursor:remoteDisconnected', args[0])
       } else if (name === 'new-chat-message') {
-        mainWindow?.webContents.send('chat:newMessage', args[0])
+        sendToRenderer('chat:newMessage', args[0])
       }
     })
 
@@ -705,7 +712,7 @@ ipcMain.handle('ot:joinDoc', async (_e, docId: string) => {
       if (name === 'otUpdateApplied') {
         const update = args[0] as { doc?: string; op?: unknown[]; v?: number } | undefined
         if (update?.doc === docId && update.op) {
-          mainWindow?.webContents.send('ot:remoteOp', {
+          sendToRenderer('ot:remoteOp', {
             docId: update.doc,
             ops: update.op,
             version: update.v
@@ -1000,7 +1007,7 @@ ipcMain.handle('overleaf:socketCompile', async (_e, mainTexRelPath: string) => {
   await compilationManager.syncBinaries(fileRefs)
 
   return compilationManager.compile(mainTexRelPath, (data) => {
-    mainWindow?.webContents.send('latex:log', data)
+    sendToRenderer('latex:log', data)
   })
 })
 
@@ -1023,6 +1030,7 @@ app.whenReady().then(async () => {
 })
 
 app.on('window-all-closed', () => {
+  mainWindow = null
   ptyInstance?.kill()
   fileSyncBridge?.stop()
   fileSyncBridge = null
diff --git a/src/renderer/src/App.css b/src/renderer/src/App.css
index 760c333..cbf0282 100644
--- a/src/renderer/src/App.css
+++ b/src/renderer/src/App.css
@@ -102,7 +102,7 @@ html, body, #root {
 .lattex-x {
   font-weight: 800;
   font-style: italic;
-  color: var(--accent-blue);
+  color: #4ECDA0;
 }
 
 .welcome-content p {
diff --git a/src/renderer/src/App.tsx b/src/renderer/src/App.tsx
index 88a351b..3259f0d 100644
--- a/src/renderer/src/App.tsx
+++ b/src/renderer/src/App.tsx
@@ -291,19 +291,14 @@ export default function App() {
           <div className="welcome-content">
             <div className="welcome-logo">
               <svg viewBox="0 0 512 512" width="96" height="96">
-                <defs>
-                  <linearGradient id="wcG" x1="0" y1="0" x2="0" y2="1"><stop offset="0%" stopColor="#FFF8E7"/><stop offset="100%" stopColor="#EDE5CE"/></linearGradient>
-                  <linearGradient id="wcC" x1="0" y1="0" x2="0" y2="1"><stop offset="0%" stopColor="#A0782C"/><stop offset="100%" stopColor="#7A5A1E"/></linearGradient>
-                </defs>
-                <circle cx="256" cy="256" r="240" fill="#6B5B3E"/>
-                <path d="M130 190 Q124 390 185 405 L327 405 Q388 390 382 190 Z" fill="url(#wcG)"/>
-                <ellipse cx="256" cy="190" rx="126" ry="36" fill="url(#wcC)"/>
-                <path d="M256 175 Q240 165 232 172 Q224 180 236 192 L256 208 L276 192 Q288 180 280 172 Q272 165 256 175Z" fill="#D4B880" opacity="0.6"/>
-                <ellipse cx="256" cy="190" rx="126" ry="36" fill="none" stroke="#D6CEBC" strokeWidth="3"/>
-                <path d="M382 230 Q435 235 438 300 Q440 365 390 370" fill="none" stroke="#FFF8E7" strokeWidth="12" strokeLinecap="round"/>
-                <path d="M216 148 Q210 118 220 95" fill="none" stroke="#FFF8E7" strokeWidth="5" strokeLinecap="round" opacity="0.5"/>
-                <path d="M256 140 Q250 105 260 80" fill="none" stroke="#FFF8E7" strokeWidth="5" strokeLinecap="round" opacity="0.45"/>
-                <path d="M296 148 Q290 118 300 95" fill="none" stroke="#FFF8E7" strokeWidth="5" strokeLinecap="round" opacity="0.4"/>
+                <rect width="512" height="512" rx="80" fill="#6B5B3E"/>
+                <path d="M148 195 Q142 375 195 395 L317 395 Q370 375 364 195 Z" fill="#FFF8E7" stroke="#EDE5CE" strokeWidth="2"/>
+                <path d="M364 235 Q410 240 412 305 Q414 365 370 370" fill="none" stroke="#FFF8E7" strokeWidth="14" strokeLinecap="round"/>
+                <ellipse cx="256" cy="195" rx="108" ry="30" fill="#4ECDA0"/>
+                <ellipse cx="256" cy="195" rx="108" ry="30" fill="none" stroke="#EDE5CE" strokeWidth="3"/>
+                <path d="M218 128 L224 108 L230 128 L250 134 L230 140 L224 160 L218 140 L198 134 Z" fill="#4ECDA0" opacity="0.9"/>
+                <path d="M268 100 L273 84 L278 100 L294 105 L278 110 L273 126 L268 110 L252 105 Z" fill="#4ECDA0" opacity="0.7"/>
+                <path d="M308 118 L313 102 L318 118 L334 123 L318 128 L313 144 L308 128 L292 123 Z" fill="#4ECDA0" opacity="0.55"/>
               </svg>
             </div>
             <h1>Latte<span className="lattex-x">X</span></h1>