feat: Notifications page, Sidebar layout fixes, and Achievements enhancements

- implemented /notifications page with overdue/upcoming alerts
- Fixed sidebar scrolling in collapsed mode
- Moved notification button to sidebar footer
- Enhanced Achievements page with streak stats and tooltips
- Improved XP history to show task titles
- Added missing translations (en/de)
- Removed top bar header
- Fixed Docker environment routing

test-results/.last-run.json

@@ -0,0 +1,6 @@
+{
+  "status": "failed",
+  "failedTests": [
+    "85c4914a209b8459e755-7f7a45c2810b205e2513"
+  ]
+}

test-results/tests-e2e_2fa_german-E2E-2-7b8cc-ization-and-Dark-Mode-Email/error-context.md

@@ -0,0 +1,38 @@
+# Page snapshot
+
+```yaml
+- generic [ref=e3]:
+  - generic [ref=e4]:
+    - generic [ref=e6]:
+      - img [ref=e8]
+      - heading "TaskFlow" [level=1] [ref=e20]
+      - paragraph [ref=e21]: Boost productivity with gamified task management and AI assistance.
+    - generic [ref=e23]:
+      - generic [ref=e24]:
+        - generic [ref=e25]: Welcome Back
+        - generic [ref=e26]: Sign in to your account to get started
+      - generic [ref=e27]:
+        - button "Login" [ref=e29] [cursor=pointer]
+        - generic [ref=e30]:
+          - generic [ref=e31]:
+            - text: Username or Email
+            - textbox "Username or Email" [ref=e32]:
+              - /placeholder: Enter username or email
+              - text: admin_1765956383406
+          - generic [ref=e33]:
+            - text: Password
+            - textbox "Password" [ref=e34]:
+              - /placeholder: Enter your password
+              - text: admin
+          - generic [ref=e35]:
+            - generic [ref=e36]:
+              - checkbox "Remember me" [ref=e37] [cursor=pointer]
+              - checkbox
+              - generic [ref=e38] [cursor=pointer]: Remember me
+            - link "Forgot password?" [ref=e39] [cursor=pointer]:
+              - /url: /forgot-password
+              - button "Forgot password?" [ref=e40]
+          - button "Sign In" [ref=e41] [cursor=pointer]
+  - region "Notifications (F8)":
+    - list
+```