style: unify thumbnail indicators on the primary blue palette

The badges on a thumbnail were a rainbow — yellow stars, blue check,
green heap pill, red discard, black duplicate — and read as five
unrelated palettes. Collapse to a single family.

PhotoThumbnail:
- Rating stars: bg-primary pill with white star icons (was yellow on
  a translucent dark backing).
- Heap basket / name chip: bg-primary (was bg-pick green).
- Duplicate badge: bg-primary (was bg-black/70).
- Discarded badge: bg-black/75 (kept neutral-dark, deliberately NOT
  blue, so "in this collection" and "trashed" never collapse into the
  same visual).
- All badges share the white outer ring + thicker icon stroke from
  the previous contrast pass.

HeapsPanel:
- Active heap row uses bg-primary/8 instead of bg-pick/10.
- Basket icon turns text-primary on the active row (was text-pick).
- "Active" pill uses bg-primary/25 + text-primary (was bg-pick/25 +
  text-pick).

The whole indicator family now reads as one consistent thing in the
brand blue.

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

frontend/src/components/heaps/HeapsPanel.tsx

@@ -266,10 +266,10 @@ export function HeapsPanel() {
                 className={clsx(
                   'group relative flex cursor-pointer items-center gap-1 rounded px-2 py-1 text-[13px]',
                   isFiltered ? 'bg-primary/20 text-primary' : 'text-text hover:bg-surface-2',
-                  // Active-heap row gets a left accent stripe so the
+                  // Active-heap row gets a soft primary wash so the
                   // user always knows where Pick / T will land, even
-                  // when navigating to a different section.
-                  isActive && !isFiltered && 'bg-pick/10 text-text',
+                  // when viewing a different section.
+                  isActive && !isFiltered && 'bg-primary/8 text-text',
                   isDropTarget && 'ring-2 ring-primary bg-primary/10'
                 )}
                 style={{ paddingLeft: '32px' }}
@@ -312,11 +312,7 @@ export function HeapsPanel() {
                 <ShoppingBasket
                   className={clsx(
                     'h-4 w-4 flex-shrink-0',
-                    isActive
-                      ? 'text-pick'
-                      : isFiltered
-                      ? 'text-primary'
-                      : 'text-text-muted'
+                    isActive || isFiltered ? 'text-primary' : 'text-text-muted'
                   )}
                 />
 
@@ -347,7 +343,7 @@ export function HeapsPanel() {
                     </span>
                     {isActive && (
                       <span
-                        className="ml-1 flex-shrink-0 rounded-full bg-pick/25 px-1.5 py-0.5 text-[9px] font-semibold uppercase tracking-wide text-pick"
+                        className="ml-1 flex-shrink-0 rounded-full bg-primary/25 px-1.5 py-0.5 text-[9px] font-semibold uppercase tracking-wide text-primary"
                         title="Active heap — Pick (P) and the basket badge on photos point here"
                       >
                         Active