Add stop-all buttons to target sections, perf chart color reset, and TODO

- Add stop-all buttons to LED targets and KC targets section headers
  (visible only when targets are running, uses headerExtra on CardSection)
- Add reset ability to performance chart color pickers (removes custom
  color from localStorage and reverts to default)
- Remove CODEBASE_REVIEW.md
- Add prioritized TODO.md with P1/P2/P3 feature roadmap

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

server/src/wled_controller/static/css/streams.css

@@ -682,10 +682,22 @@
     flex-shrink: 0;
 }
 
-.cs-collapsed .cs-filter-wrap {
+.cs-collapsed .cs-filter-wrap,
+.cs-collapsed .cs-header-extra {
     display: none;
 }
 
+.cs-header-extra {
+    display: flex;
+    align-items: center;
+}
+
+.cs-header-extra .btn {
+    padding: 2px 8px;
+    font-size: 0.75rem;
+    line-height: 1;
+}
+
 .cs-filter-wrap {
     position: relative;
     margin-left: auto;