Fix SearchBar — align button height with input, tighten icon gap

- Explicit button height via input token CSS vars for pixel-perfect alignment
- Reduced InputAdornment start margin (mr: 0.5) to bring search icon closer to text

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/components/molecules/SearchBar/SearchBar.tsx

@@ -150,6 +150,10 @@ export const SearchBar = React.forwardRef<HTMLDivElement, SearchBarProps>(
           inputProps={{
             'aria-label': ariaLabel,
           }}
+          sx={{
+            // Tighten the gap between search icon and text
+            '& .MuiInputAdornment-positionStart': { mr: 0.5 },
+          }}
         />
 
         {showButton && (
@@ -159,7 +163,11 @@ export const SearchBar = React.forwardRef<HTMLDivElement, SearchBarProps>(
             onClick={handleSubmit}
             disabled={disabled || !value.trim()}
             loading={loading}
-            sx={{ flexShrink: 0 }}
+            sx={{
+              flexShrink: 0,
+              // Explicit height to match input — FormControl wrapper can offset alignment
+              height: size === 'medium' ? 'var(--fa-input-height-md)' : 'var(--fa-input-height-sm)',
+            }}
           >
             {buttonLabel}
           </Button>