feat(ui): enable window dragging from header bar

- Add core:window:allow-start-dragging permission
- Set data-tauri-drag-region on header bar
- Exclude interactive buttons from drag region
- Configure macOS overlay title bar style

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: fazxes

src-tauri/capabilities/default.json

@@ -9,6 +9,7 @@
     "core:window:allow-maximize",
     "core:window:allow-set-size",
     "core:window:allow-set-title",
+    "core:window:allow-start-dragging",
     "core:event:allow-listen",
     "core:event:allow-emit",
     "dialog:allow-open",

src-tauri/tauri.conf.json

@@ -22,7 +22,9 @@
         "fullscreen": false,
         "decorations": true,
         "transparent": false,
-        "center": true
+        "center": true,
+        "titleBarStyle": "overlay",
+        "hiddenTitle": true
       }
     ],
     "security": {

src/components/layout/header-bar.tsx

@@ -25,6 +25,7 @@ const TabButton: FC<TabButtonProps> = ({ label, active, onClick }) => {
       role="tab"
       aria-selected={active}
       tabIndex={active ? 0 : -1}
+      data-tauri-drag-region={false}
       className={cn(
         'relative flex items-center justify-center transition-colors h-7 px-3',
         active ? 'text-foreground' : 'text-muted-foreground hover:text-foreground'
@@ -61,14 +62,17 @@ export const HeaderBar: FC<HeaderBarProps> = ({ className }) => {
 
   return (
     <header
+      data-tauri-drag-region
       className={cn(
-        'h-[35px] flex items-center justify-between px-4 border-b border-border shrink-0',
+        'h-[35px] flex items-center justify-between pr-4 border-b border-border shrink-0',
         'bg-sidebar',
+        // Left padding for macOS traffic light buttons (about 78px)
+        'pl-[78px]',
         className
       )}
     >
-      {/* Left spacer for balance */}
-      <div className="w-[200px]" />
+      {/* Left spacer for balance (reduced since we have traffic light padding) */}
+      <div className="w-[122px]" />
 
       {/* Center tabs */}
       <div className="flex items-center gap-0.5" role="tablist" aria-orientation="horizontal">
@@ -98,6 +102,7 @@ export const HeaderBar: FC<HeaderBarProps> = ({ className }) => {
       {/* Right search button */}
       <div className="w-[200px] flex justify-end">
         <button
+          data-tauri-drag-region={false}
           className="flex items-center h-6 rounded-md text-muted-foreground hover:text-foreground transition-colors overflow-hidden border border-border dark:border-border/50 bg-muted/50 hover:bg-muted"
           title="Search files (⌘P)"
           onClick={handleOpenSearch}