fix: resolve 7 critical UI issues - charts, layouts, and mobile responsiveness

This commit fixes all reported UI issues across the dashboard:

## Issue 1: Chart Colors and Tooltips ✅
- Create chartColors utility with static hex colors for Recharts compatibility
- Replace CSS variable colors (hsl(var(--))) with hex colors in all charts
- Add custom tooltip styling with dark background and white text for readability
- Fixes: ProcessStateChart, ProcessUptimeChart, GroupStatistics

## Issue 2: Process Card Heights ✅
- Add h-full and flex flex-col to ProcessCard component
- Add auto-rows-fr to process grid layout
- Ensures all cards have consistent heights regardless of content

## Issue 3: Batch Actions Button Labels ✅
- Simplify button labels from "Start Selected" to "Start"
- Remove "Stop Selected" to "Stop", "Restart Selected" to "Restart"
- Labels now always visible on all screen sizes

## Issue 4: Mobile Menu Background ✅
- Change mobile menu from semi-transparent (bg-background/95) to solid (bg-background)
- Removes backdrop blur for better visibility

## Issue 5: Group Header Button Overflow ✅
- Add flex-wrap to button container in GroupCard
- Stack buttons vertically on mobile (flex-col md:flex-row)
- Buttons take full width on mobile, auto width on desktop

## Issue 6: Logs Search Input Overflow ✅
- Change LogSearch from max-w-md to w-full sm:flex-1 sm:max-w-md
- Search input now full width on mobile, constrained on desktop

## Issue 7: Logs Action Button Overflow ✅
- Add flex-wrap to LogControls button container
- Buttons wrap to new row when space is limited

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

components/layout/Navbar.tsx

@@ -116,7 +116,7 @@ export function Navbar() {
 
       {/* Mobile Menu Drawer */}
       {mobileMenuOpen && (
-        <div className="md:hidden fixed inset-0 top-16 z-50 bg-background/95 backdrop-blur-sm">
+        <div className="md:hidden fixed inset-0 top-16 z-50 bg-background">
           <div className="container px-4 py-6">
             <nav className="flex flex-col gap-2">
               {navItems.map((item) => (