fix(sweetlink): bind --serve to 0.0.0.0 + clipboard fallback for file://

Fixes two issues from hook feedback:

1. report --serve: Now binds to 0.0.0.0 (all interfaces) instead of
   loopback. Prints both local and network URLs with LAN IP auto-detection.
   Other devices on the network can now access the served viewer.

2. Viewer Copy Report: Falls back to document.execCommand('copy') when
   navigator.clipboard is unavailable (file:// contexts, non-HTTPS).
   The downloaded standalone viewer now works offline for clipboard copy.

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

Author: ytspar

packages/sweetlink/src/cli/sweetlink.ts

@@ -2874,9 +2874,22 @@ async function handleStatusCommand(): Promise<StatusData> {
             res.writeHead(200, { 'Content-Type': 'text/html; charset=utf-8' });
             res.end(viewerContent);
           });
-          server.listen(port, () => {
-            const url = `http://localhost:${port}`;
-            console.log(`[Sweetlink] Serving viewer at ${url}`);
+          server.listen(port, '0.0.0.0', () => {
+            const os = require('os');
+            const nets = os.networkInterfaces();
+            let lanIp = 'localhost';
+            for (const name of Object.keys(nets)) {
+              for (const net of nets[name]) {
+                if (net.family === 'IPv4' && !net.internal) {
+                  lanIp = net.address;
+                  break;
+                }
+              }
+              if (lanIp !== 'localhost') break;
+            }
+            console.log(`[Sweetlink] Serving viewer at:`);
+            console.log(`  Local:   http://localhost:${port}`);
+            console.log(`  Network: http://${lanIp}:${port}`);
             console.log('  Press Ctrl+C to stop.');
           });
           // Keep running until Ctrl+C

packages/sweetlink/src/daemon/viewer.ts

@@ -524,10 +524,26 @@ document.addEventListener('keydown', function(e) {
 
 // Start at first action
 // Share buttons
+// Clipboard helper — falls back to execCommand for file:// contexts
+function copyToClipboard(text) {
+  if (navigator.clipboard && window.isSecureContext) {
+    return navigator.clipboard.writeText(text);
+  }
+  // Fallback for file:// or non-secure contexts
+  var textarea = document.createElement('textarea');
+  textarea.value = text;
+  textarea.style.cssText = 'position:fixed;left:-9999px';
+  document.body.appendChild(textarea);
+  textarea.select();
+  var ok = document.execCommand('copy');
+  document.body.removeChild(textarea);
+  return ok ? Promise.resolve() : Promise.reject(new Error('execCommand failed'));
+}
+
 var btnCopyReport = document.getElementById('btn-copy-report');
 if (btnCopyReport) {
   btnCopyReport.addEventListener('click', function() {
-    navigator.clipboard.writeText(summaryReport).then(function() {
+    copyToClipboard(summaryReport).then(function() {
       btnCopyReport.textContent = 'Copied!';
       btnCopyReport.classList.add('copied');
       setTimeout(function() {