fix(styles): resolve design system audit violations

- Replace off-grid spacing (3px, 5px) with space tokens (--space-0h, --space-1)
- Replace below-minimum font-size 9px with var(--text-xs) in calendar, dashboard, notes
- Replace hardcoded 2.5rem with var(--text-4xl) in weather widget
- Replace hardcoded box-shadow with var(--shadow-sm) in toggle thumb
- Replace 0.85em and #666 with type/color tokens in print styles

public/styles/budget.css

@@ -304,7 +304,7 @@
   gap: var(--space-2);
   background-color: var(--color-surface-2);
   border-radius: var(--radius-sm);
-  padding: 3px;
+  padding: var(--space-0h);
 }
 
 .amount-type-btn {

public/styles/calendar.css

@@ -505,7 +505,7 @@
   display: inline-flex;
   align-items: center;
   justify-content: center;
-  font-size: 9px;
+  font-size: var(--text-xs);
   font-weight: var(--font-weight-bold);
   color: #ffffff;
   flex-shrink: 0;

public/styles/dashboard.css

@@ -311,7 +311,7 @@
   display: flex;
   align-items: center;
   justify-content: center;
-  font-size: 9px;
+  font-size: var(--text-xs);
   font-weight: var(--font-weight-bold);
   color: #ffffff;
   flex-shrink: 0;
@@ -805,7 +805,7 @@
   }
 
   .weather-widget__temp {
-    font-size: 2.5rem;
+    font-size: var(--text-4xl);
   }
 
   .weather-widget__icon {

public/styles/layout.css

@@ -1034,7 +1034,7 @@
   height: 20px;
   background: #fff;
   border-radius: var(--radius-full);
-  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.15);
+  box-shadow: var(--shadow-sm);
   transition: transform 0.2s var(--ease-out);
 }
 
@@ -1540,8 +1540,8 @@
 
   a[href]::after {
     content: " (" attr(href) ")";
-    font-size: 0.85em;
-    color: #666;
+    font-size: var(--text-sm);
+    color: var(--color-text-secondary);
   }
 
   .nav-item,

public/styles/notes.css

@@ -213,7 +213,7 @@
   display: inline-flex;
   align-items: center;
   justify-content: center;
-  font-size: 9px;
+  font-size: var(--text-xs);
   font-weight: var(--font-weight-bold);
   color: #ffffff;
   flex-shrink: 0;

public/styles/tasks.css

@@ -56,7 +56,7 @@
   display: flex;
   background-color: var(--color-surface-2);
   border-radius: var(--radius-sm);
-  padding: 3px;
+  padding: var(--space-0h);
   gap: 2px;
 }
 
@@ -467,7 +467,7 @@
   justify-content: center;
   min-width: 18px;
   height: 18px;
-  padding: 0 5px;
+  padding: 0 var(--space-1);
   border-radius: var(--radius-full);
   background-color: var(--color-danger);
   color: #fff;