fix: freehand drawing, click highlight, mobile toolbar visibility

Freehand drawing fix:
- Disable dragPan when in freehand mode (was only disabling dblclick
  zoom). Without this, clicks were interpreted as pan gestures.
- Re-enable dragPan when exiting freehand mode.

Click highlight:
- Clicking a parcel in "off" mode now highlights it with the selection
  layer (amber fill + orange outline). Clicking empty space clears it.
- Provides visual feedback for which parcel was clicked.

Mobile toolbar:
- Moved selection toolbar higher (bottom-12 on mobile) with z-20
  to ensure it's above MapLibre attribution bar.

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

src/app/(portal)/portal/page.tsx

@@ -1597,8 +1597,8 @@ function HartaContent() {
                 )}
               </div>
 
-              {/* Bottom: selection toolbar — centered on mobile, above attribution */}
-              <div className="absolute bottom-8 left-1/2 -translate-x-1/2 sm:left-3 sm:translate-x-0 z-10">
+              {/* Bottom: selection toolbar — centered, above attribution */}
+              <div className="absolute bottom-12 sm:bottom-8 left-1/2 -translate-x-1/2 sm:left-3 sm:translate-x-0 z-20">
                 <SelectionToolbar
                   selectedFeatures={selectedFeatures}
                   selectionMode={selectionMode}