diff --git a/src-tauri/src/notifications.rs b/src-tauri/src/notifications.rs
index 5b12d89..590fc35 100644
--- a/src-tauri/src/notifications.rs
+++ b/src-tauri/src/notifications.rs
@@ -38,6 +38,46 @@ fn format_simple_notification(title: &str, body: &str) -> String {
     format!("{}\n\n{}", title, body)
 }
 
+/// Build notify-send command for testing (doesn't execute)
+#[cfg(test)]
+fn build_notify_send_command(title: &str, body: &str) -> (String, Vec<String>) {
+    (
+        "notify-send".to_string(),
+        vec![
+            title.to_string(),
+            body.to_string(),
+            "--urgency=normal".to_string(),
+            "--app-name=Hikari Desktop".to_string(),
+        ],
+    )
+}
+
+/// Build Windows PowerShell command for testing (doesn't execute)
+#[cfg(test)]
+fn build_windows_powershell_command(title: &str, body: &str) -> (String, Vec<String>) {
+    let script = generate_powershell_toast_script(title, body);
+    (
+        "pwsh.exe".to_string(),
+        vec![
+            "-NoProfile".to_string(),
+            "-WindowStyle".to_string(),
+            "Hidden".to_string(),
+            "-Command".to_string(),
+            script,
+        ],
+    )
+}
+
+/// Build simple notification command for testing (doesn't execute)
+#[cfg(test)]
+fn build_simple_notification_command(title: &str, body: &str) -> (String, Vec<String>) {
+    let message = format_simple_notification(title, body);
+    (
+        "cmd.exe".to_string(),
+        vec!["/c".to_string(), "msg".to_string(), "*".to_string(), message],
+    )
+}
+
 #[command]
 pub async fn send_notify_send(title: String, body: String) -> Result<(), String> {
     // Use notify-send for Linux/WSL
@@ -210,4 +250,141 @@ mod tests {
         assert!(script.contains("`\"Quoted`\" `\"Multiple`\" `\"Times`\""));
         assert!(script.contains("`\"More`\" `\"Quotes`\" `\"Here`\""));
     }
+
+    // E2E Integration Tests - Command Structure Verification
+
+    #[test]
+    fn test_e2e_notify_send_command_structure() {
+        let (command, args) = build_notify_send_command("Test Title", "Test Body");
+
+        assert_eq!(command, "notify-send");
+        assert_eq!(args.len(), 4);
+        assert_eq!(args[0], "Test Title");
+        assert_eq!(args[1], "Test Body");
+        assert_eq!(args[2], "--urgency=normal");
+        assert_eq!(args[3], "--app-name=Hikari Desktop");
+    }
+
+    #[test]
+    fn test_e2e_notify_send_with_special_chars() {
+        let (command, args) =
+            build_notify_send_command("Title with \"quotes\"", "Body\nwith\nnewlines");
+
+        assert_eq!(command, "notify-send");
+        assert_eq!(args[0], "Title with \"quotes\"");
+        assert_eq!(args[1], "Body\nwith\nnewlines");
+        // notify-send handles these directly
+    }
+
+    #[test]
+    fn test_e2e_windows_powershell_command_structure() {
+        let (command, args) = build_windows_powershell_command("Test Title", "Test Body");
+
+        assert_eq!(command, "pwsh.exe");
+        assert_eq!(args.len(), 5);
+        assert_eq!(args[0], "-NoProfile");
+        assert_eq!(args[1], "-WindowStyle");
+        assert_eq!(args[2], "Hidden");
+        assert_eq!(args[3], "-Command");
+
+        // Verify the script in args[4] contains expected elements
+        let script = &args[4];
+        assert!(script.contains("Test Title"));
+        assert!(script.contains("Test Body"));
+        assert!(script.contains("Hikari Desktop"));
+        assert!(script.contains("ToastNotification"));
+    }
+
+    #[test]
+    fn test_e2e_windows_powershell_quote_escaping() {
+        let (_, args) =
+            build_windows_powershell_command("Title with \"quotes\"", "Body with \"quotes\"");
+
+        let script = &args[4];
+        // Verify quotes are properly escaped in the PowerShell script
+        assert!(script.contains("Title with `\"quotes`\""));
+        assert!(script.contains("Body with `\"quotes`\""));
+    }
+
+    #[test]
+    fn test_e2e_simple_notification_command_structure() {
+        let (command, args) = build_simple_notification_command("Test Title", "Test Body");
+
+        assert_eq!(command, "cmd.exe");
+        assert_eq!(args.len(), 4);
+        assert_eq!(args[0], "/c");
+        assert_eq!(args[1], "msg");
+        assert_eq!(args[2], "*");
+        assert_eq!(args[3], "Test Title\n\nTest Body");
+    }
+
+    #[test]
+    fn test_e2e_simple_notification_multiline() {
+        let (_, args) =
+            build_simple_notification_command("Multi\nLine\nTitle", "Multi\nLine\nBody");
+
+        let message = &args[3];
+        assert!(message.contains("Multi\nLine\nTitle"));
+        assert!(message.contains("\n\n"));
+        assert!(message.contains("Multi\nLine\nBody"));
+    }
+
+    #[test]
+    fn test_e2e_command_consistency_across_platforms() {
+        // Test that different platforms use consistent parameters
+        let title = "Consistency Test";
+        let body = "Testing cross-platform consistency";
+
+        // Linux command
+        let (notify_cmd, notify_args) = build_notify_send_command(title, body);
+        assert!(notify_cmd.contains("notify"));
+        assert!(notify_args.iter().any(|arg| arg.contains("Hikari Desktop")));
+
+        // Windows PowerShell command
+        let (ps_cmd, ps_args) = build_windows_powershell_command(title, body);
+        assert!(ps_cmd.contains("pwsh") || ps_cmd.contains("powershell"));
+        let ps_script = &ps_args[4];
+        assert!(ps_script.contains("Hikari Desktop"));
+
+        // Windows simple command
+        let (msg_cmd, msg_args) = build_simple_notification_command(title, body);
+        assert!(msg_cmd.contains("cmd"));
+        assert!(msg_args[3].contains(title));
+        assert!(msg_args[3].contains(body));
+    }
+
+    #[test]
+    fn test_e2e_unicode_support_across_platforms() {
+        let title = "日本語 Title";
+        let body = "Unicode: 🎉";
+
+        // Verify all platforms preserve unicode
+        let (_, notify_args) = build_notify_send_command(title, body);
+        assert_eq!(notify_args[0], title);
+        assert_eq!(notify_args[1], body);
+
+        let (_, ps_args) = build_windows_powershell_command(title, body);
+        let ps_script = &ps_args[4];
+        assert!(ps_script.contains(title));
+        assert!(ps_script.contains(body));
+
+        let (_, msg_args) = build_simple_notification_command(title, body);
+        assert!(msg_args[3].contains(title));
+        assert!(msg_args[3].contains(body));
+    }
+
+    #[test]
+    fn test_e2e_empty_input_handling() {
+        // Test that empty inputs are handled gracefully
+        let (_, notify_args) = build_notify_send_command("", "");
+        assert_eq!(notify_args[0], "");
+        assert_eq!(notify_args[1], "");
+
+        let (_, ps_args) = build_windows_powershell_command("", "");
+        let ps_script = &ps_args[4];
+        assert!(ps_script.contains("Hikari Desktop")); // Still has app name
+
+        let (_, msg_args) = build_simple_notification_command("", "");
+        assert_eq!(msg_args[3], "\n\n");
+    }
 }
diff --git a/src/lib/components/McpManagementPanel.svelte b/src/lib/components/McpManagementPanel.svelte
index aa798b1..81f4970 100644
--- a/src/lib/components/McpManagementPanel.svelte
+++ b/src/lib/components/McpManagementPanel.svelte
@@ -12,7 +12,7 @@
     command: string | null;
     url: string | null;
     transport: string; // "stdio", "http", or "sse"
-    env: any | null;
+    env: Record<string, string> | null;
     status: string | null; // "Connected" or "Failed to connect"
   }
 
@@ -402,8 +402,8 @@
             <!-- Actions -->
             <div class="pt-4 border-t border-[var(--border-color)]">
               <button
-                onclick={() => removeServer(selectedServer.name)}
-                disabled={actionInProgress === selectedServer.name}
+                onclick={() => selectedServer && removeServer(selectedServer.name)}
+                disabled={actionInProgress === selectedServer?.name}
                 class="w-full px-4 py-2 bg-red-500/20 border border-red-500/30 rounded-lg text-sm text-red-400 hover:bg-red-500/30 transition-colors disabled:opacity-40 disabled:cursor-not-allowed flex items-center justify-center gap-2"
               >
                 <Trash2 class="w-4 h-4" />
diff --git a/src/lib/components/SessionHistoryPanel.svelte b/src/lib/components/SessionHistoryPanel.svelte
index e674cac..d237060 100644
--- a/src/lib/components/SessionHistoryPanel.svelte
+++ b/src/lib/components/SessionHistoryPanel.svelte
@@ -17,8 +17,21 @@
   let isImporting = $state(false);
   let showClearAllConfirm = $state(false);
 
-  const sessions = $derived(sessionsStore.sessions);
-  const isLoading = $derived(sessionsStore.isLoading);
+  let sessions = $state<SessionListItem[]>([]);
+  let isLoading = $state(false);
+
+  $effect(() => {
+    const unsubSessions = sessionsStore.sessions.subscribe((value) => {
+      sessions = value;
+    });
+    const unsubLoading = sessionsStore.isLoading.subscribe((value) => {
+      isLoading = value;
+    });
+    return () => {
+      unsubSessions();
+      unsubLoading();
+    };
+  });
 
   onMount(() => {
     sessionsStore.loadSessions();
@@ -303,11 +316,11 @@
       </div>
 
       <div class="overflow-y-auto flex-1">
-        {#if $isLoading}
+        {#if isLoading}
           <div class="flex items-center justify-center p-8">
             <div class="text-[var(--text-tertiary)]">Loading sessions...</div>
           </div>
-        {:else if $sessions.length === 0}
+        {:else if sessions.length === 0}
           <div class="flex flex-col items-center justify-center p-8 text-center">
             <svg
               class="w-16 h-16 text-[var(--text-tertiary)] mb-4"
@@ -329,7 +342,7 @@
           </div>
         {:else}
           <div class="divide-y divide-[var(--border-color)]">
-            {#each $sessions as session (session.id)}
+            {#each sessions as session (session.id)}
               <div class="p-4 hover:bg-[var(--bg-secondary)] transition-colors group">
                 <div class="flex items-start justify-between gap-4">
                   <button class="flex-1 text-left" onclick={() => handleViewSession(session)}>
@@ -451,7 +464,6 @@
 </div>
 
 {#if showClearAllConfirm}
-  <!-- svelte-ignore a11y_no_static_element_interactions -->
   <div
     class="fixed inset-0 bg-black/50 backdrop-blur-sm z-[60] flex items-center justify-center p-4"
     onclick={() => (showClearAllConfirm = false)}
@@ -459,7 +471,6 @@
     tabindex="0"
     onkeydown={(e) => e.key === "Escape" && (showClearAllConfirm = false)}
   >
-    <!-- svelte-ignore a11y_no_static_element_interactions a11y_click_events_have_key_events -->
     <div
       class="bg-[var(--bg-primary)] border border-red-500/30 rounded-lg shadow-xl max-w-md w-full p-6"
       onclick={(e) => e.stopPropagation()}
diff --git a/src/lib/components/TodoPanel.svelte b/src/lib/components/TodoPanel.svelte
index 6245f31..7125de7 100644
--- a/src/lib/components/TodoPanel.svelte
+++ b/src/lib/components/TodoPanel.svelte
@@ -1,5 +1,5 @@
 <script lang="ts">
-  import { todos, type TodoItem } from "$lib/stores/todos";
+  import { todos } from "$lib/stores/todos";
   import { CheckCircle, Circle, Loader } from "lucide-svelte";
 
   interface Props {
diff --git a/src/lib/stores/config.test.ts b/src/lib/stores/config.test.ts
index db65871..5f9e625 100644
--- a/src/lib/stores/config.test.ts
+++ b/src/lib/stores/config.test.ts
@@ -722,6 +722,9 @@ describe("config store", () => {
     it("handles save errors gracefully without losing data", async () => {
       const mockInvokeImpl = vi.mocked(invoke);
 
+      // Mock console.error to suppress expected error output
+      const consoleErrorSpy = vi.spyOn(console, "error").mockImplementation(() => {});
+
       // Set initial config
       await configStore.updateConfig({ font_size: 14 });
 
@@ -733,6 +736,12 @@ describe("config store", () => {
 
       // Original config should still be accessible
       expect(configStore.getConfig().font_size).toBe(14);
+
+      // Verify error was logged
+      expect(consoleErrorSpy).toHaveBeenCalledWith("Failed to save config:", expect.any(Error));
+
+      // Restore console.error
+      consoleErrorSpy.mockRestore();
     });
   });
 
diff --git a/src/lib/tauri.ts b/src/lib/tauri.ts
index 0e9a19c..7e42c1f 100644
--- a/src/lib/tauri.ts
+++ b/src/lib/tauri.ts
@@ -466,7 +466,6 @@ export async function initializeDiscordRpc() {
 
       console.log("Discord RPC initialized successfully with initial presence");
     } catch (error) {
-      const errorMessage = error instanceof Error ? error.message : String(error);
       console.error("Failed to initialize Discord RPC:", error);
       console.warn("Discord RPC will be unavailable. Make sure Discord is running.");
     }