fix: Add padding to sidebar headers to prevent X button overlap

Added pr-8 to header flex containers in:
- ArchiveSidebar
- ActivitySidebar
- ConflictResolver
- PreviewPanel

The Sheet component's close button is positioned absolute at right-4,
which was overlapping with action buttons (refresh, trash, etc.)

server/.veritas-kanban/activity.json

@@ -1,4 +1,88 @@
 [
+  {
+    "id": "activity_1769449185820_cctph1fac",
+    "type": "task_deleted",
+    "taskId": "task_20260126_tsDVOq",
+    "taskTitle": "Test feature branch",
+    "timestamp": "2026-01-26T17:39:45.820Z"
+  },
+  {
+    "id": "activity_1769449175512_6lvnf3bgl",
+    "type": "task_updated",
+    "taskId": "task_20260126_tsDVOq",
+    "taskTitle": "Test feature branch",
+    "timestamp": "2026-01-26T17:39:35.512Z"
+  },
+  {
+    "id": "activity_1769448961158_7hmywa016",
+    "type": "status_changed",
+    "taskId": "task_20260126_9VIZY1",
+    "taskTitle": "Test task from CLI",
+    "details": {
+      "from": "archived",
+      "status": "done"
+    },
+    "timestamp": "2026-01-26T17:36:01.158Z"
+  },
+  {
+    "id": "activity_1769448955837_m815ex2dh",
+    "type": "task_archived",
+    "taskId": "task_20260126_9VIZY1",
+    "taskTitle": "Test task from CLI",
+    "timestamp": "2026-01-26T17:35:55.837Z"
+  },
+  {
+    "id": "activity_1769448944900_dm04m4zyu",
+    "type": "status_changed",
+    "taskId": "task_20260126_9VIZY1",
+    "taskTitle": "Test task from CLI",
+    "details": {
+      "from": "in-progress",
+      "status": "done"
+    },
+    "timestamp": "2026-01-26T17:35:44.900Z"
+  },
+  {
+    "id": "activity_1769448691266_xbovau2j5",
+    "type": "task_updated",
+    "taskId": "task_20260126_tsDVOq",
+    "taskTitle": "Test feature branch",
+    "timestamp": "2026-01-26T17:31:31.266Z"
+  },
+  {
+    "id": "activity_1769448671292_o56r391ij",
+    "type": "task_created",
+    "taskId": "task_20260126_tsDVOq",
+    "taskTitle": "Test feature branch",
+    "details": {
+      "type": "code",
+      "priority": "medium",
+      "project": "test"
+    },
+    "timestamp": "2026-01-26T17:31:11.292Z"
+  },
+  {
+    "id": "activity_1769448643552_50ghtkm2u",
+    "type": "status_changed",
+    "taskId": "task_20260126_9VIZY1",
+    "taskTitle": "Test task from CLI",
+    "details": {
+      "from": "todo",
+      "status": "in-progress"
+    },
+    "timestamp": "2026-01-26T17:30:43.552Z"
+  },
+  {
+    "id": "activity_1769448480165_c8bcel8bk",
+    "type": "task_created",
+    "taskId": "task_20260126_9VIZY1",
+    "taskTitle": "Test task from CLI",
+    "details": {
+      "type": "code",
+      "priority": "high"
+    },
+    "timestamp": "2026-01-26T17:28:00.165Z"
+  },
   {
     "id": "activity_1769447559137_w5so806no",
     "type": "status_changed",

web/src/components/layout/ActivitySidebar.tsx

@@ -107,7 +107,7 @@ export function ActivitySidebar({ open, onOpenChange }: ActivitySidebarProps) {
     <Sheet open={open} onOpenChange={onOpenChange}>
       <SheetContent side="right" className="w-[400px] sm:w-[450px] p-0">
         <SheetHeader className="px-4 py-3 border-b">
-          <div className="flex items-center justify-between">
+          <div className="flex items-center justify-between pr-8">
             <SheetTitle className="flex items-center gap-2">
               <Activity className="h-5 w-5" />
               Activity Log

web/src/components/layout/ArchiveSidebar.tsx

@@ -177,7 +177,7 @@ export function ArchiveSidebar({ open, onOpenChange, onTaskClick }: ArchiveSideb
     <Sheet open={open} onOpenChange={onOpenChange}>
       <SheetContent side="right" className="w-[400px] sm:w-[450px] p-0">
         <SheetHeader className="px-4 py-3 border-b">
-          <div className="flex items-center justify-between">
+          <div className="flex items-center justify-between pr-8">
             <SheetTitle className="flex items-center gap-2">
               <Archive className="h-5 w-5" />
               Archive

web/src/components/task/ConflictResolver.tsx

@@ -126,7 +126,7 @@ export function ConflictResolver({ task, open, onOpenChange }: ConflictResolverP
       <Sheet open={open} onOpenChange={onOpenChange}>
         <SheetContent side="right" className="w-[90vw] sm:max-w-[1200px] p-0 flex flex-col">
           <SheetHeader className="px-6 py-4 border-b">
-            <div className="flex items-center justify-between">
+            <div className="flex items-center justify-between pr-8">
               <div>
                 <SheetTitle className="flex items-center gap-2">
                   <AlertTriangle className="h-5 w-5 text-amber-500" />

web/src/components/task/PreviewPanel.tsx

@@ -67,7 +67,7 @@ export function PreviewPanel({ task, open, onOpenChange }: PreviewPanelProps) {
     <Sheet open={open} onOpenChange={onOpenChange}>
       <SheetContent side="right" className="w-[800px] sm:max-w-[800px] p-0 flex flex-col">
         <SheetHeader className="px-6 py-4 border-b">
-          <div className="flex items-center justify-between">
+          <div className="flex items-center justify-between pr-8">
             <div>
               <SheetTitle className="flex items-center gap-2">
                 <Monitor className="h-5 w-5" />