feat: Add a back button to the agent search screen and adjust the search bar's left padding.

lib/features/agents/presentation/screens/agent_detail_screen.dart

@@ -102,8 +102,38 @@ class _AgentDetailScreenState extends ConsumerState<AgentDetailScreen> {
         physics: const AlwaysScrollableScrollPhysics(),
         child: Column(
         children: [
+          // ── Back Button ──
+          Padding(
+            padding: const EdgeInsets.fromLTRB(16, 8, 16, 0),
+            child: Align(
+              alignment: Alignment.centerLeft,
+              child: GestureDetector(
+                onTap: () {
+                  if (Navigator.of(context).canPop()) {
+                    Navigator.of(context).pop();
+                  } else {
+                    context.go('/home');
+                  }
+                },
+                child: Container(
+                  width: 36,
+                  height: 36,
+                  decoration: BoxDecoration(
+                    color: AppColors.primaryDark.withValues(alpha: 0.08),
+                    shape: BoxShape.circle,
+                  ),
+                  child: const Icon(
+                    Icons.arrow_back_ios_new_rounded,
+                    color: AppColors.primaryDark,
+                    size: 18,
+                  ),
+                ),
+              ),
+            ),
+          ),
+
           // ── Avatar Section ──
-          const SizedBox(height: 16),
+          const SizedBox(height: 8),
           _buildAvatarSection(agent),
 
           // ── Status + Connect Buttons ──