feat(09-05): add helpTextPrefix prop and fix tooltip placement + hover behavior

- TextFieldMD3: add helpTextPrefix prop rendered inline left of helpText
- Guard changed to (helpText || helpTextPrefix) so icon renders without helpText
- FieldRenderer: move tooltip icon from above field to inline with helpText via helpTextPrefix
- FieldRenderer: add hoverTooltip state; tooltip visible on mouseEnter, dismisses on mouseLeave
- FieldRenderer: click-to-unpin clears hoverTooltip to prevent sticky tooltip after dismiss
- PasswordField: same tooltip fix as FieldRenderer text-branch
- Select-branch also gains hover support

src/components/ui/PasswordField.tsx

@@ -14,6 +14,7 @@ interface PasswordFieldProps {
 export function PasswordField({ id, label, error, registration, helpText, tooltipText }: PasswordFieldProps) {
   const [show, setShow] = useState(false);
   const [showTooltip, setShowTooltip] = useState(false);
+  const [hoverTooltip, setHoverTooltip] = useState(false);
 
   const toggleButton = (
     <button
@@ -26,23 +27,23 @@ export function PasswordField({ id, label, error, registration, helpText, toolti
     </button>
   );
 
+  const tooltipIcon = tooltipText ? (
+    <button
+      type="button"
+      onClick={() => { setShowTooltip(v => { if (v) setHoverTooltip(false); return !v; }); }}
+      onMouseEnter={() => setHoverTooltip(true)}
+      onMouseLeave={() => setHoverTooltip(false)}
+      aria-label={`More info about ${label}`}
+      className="text-primary hover:text-primary/80 text-xs leading-none mt-px shrink-0"
+    >
+      ⓘ
+    </button>
+  ) : undefined;
+
+  const tooltipVisible = showTooltip || hoverTooltip;
+
   return (
     <div className="flex flex-col gap-1">
-      {tooltipText && (
-        <button
-          type="button"
-          onClick={() => setShowTooltip(v => !v)}
-          aria-label={`More info about ${label}`}
-          className="text-primary hover:text-primary text-xs leading-none self-start"
-        >
-          ⓘ
-        </button>
-      )}
-      {tooltipText && showTooltip && (
-        <p className="text-xs text-primary bg-primary/10 border border-primary/30 rounded px-2 py-1.5">
-          {tooltipText}
-        </p>
-      )}
       <TextFieldMD3
         id={id}
         label={label}
@@ -50,8 +51,14 @@ export function PasswordField({ id, label, error, registration, helpText, toolti
         registration={registration}
         type={show ? 'text' : 'password'}
         helpText={helpText}
+        helpTextPrefix={tooltipIcon}
         suffix={toggleButton}
       />
+      {tooltipText && tooltipVisible && (
+        <p className="text-xs text-primary bg-primary/10 border border-primary/30 rounded px-2 py-1.5">
+          {tooltipText}
+        </p>
+      )}
     </div>
   );
 }