feat(client): add Timestamp component, ESLint 10 + Prettier, and code quality fixes

- add Timestamp component with moment relative time and ISO tooltip
- add Timestamp stories (JustNow, MinutesAgo, HoursAgo, DaysAgo, MonthsAgo)
- add ESLint 10 with typescript-eslint, react-hooks, react-refresh, prettier
- add Prettier config with singleQuote, semi, trailingComma all, printWidth 100
- add lint, lint:fix, format, test:storybook scripts to package.json
- fix react-hooks/set-state-in-effect in all page components
- auto-fix 113 Prettier formatting issues across src and .storybook

client/.storybook/stories/SidePanel.stories.tsx

@@ -5,7 +5,16 @@ const NAV_ITEMS = ['Dashboard', 'Scenarios', 'Environments', 'Reports', 'Setting
 
 function NavList() {
   return (
-    <ul style={{ listStyle: 'none', margin: 0, padding: 0, display: 'flex', flexDirection: 'column', gap: 2 }}>
+    <ul
+      style={{
+        listStyle: 'none',
+        margin: 0,
+        padding: 0,
+        display: 'flex',
+        flexDirection: 'column',
+        gap: 2,
+      }}
+    >
       {NAV_ITEMS.map((item) => (
         <li key={item}>
           <button
@@ -41,7 +50,14 @@ const meta: Meta<typeof SidePanel> = {
     (Story) => (
       <div style={{ display: 'flex', height: 420, background: 'var(--color-bg)' }}>
         <Story />
-        <div style={{ flex: 1, padding: 'var(--space-6)', color: 'var(--color-text-muted)', fontSize: 'var(--font-size-sm)' }}>
+        <div
+          style={{
+            flex: 1,
+            padding: 'var(--space-6)',
+            color: 'var(--color-text-muted)',
+            fontSize: 'var(--font-size-sm)',
+          }}
+        >
           Main content area
         </div>
       </div>