Implement EMBA Specialization Solver web app

Full React+TypeScript app with LP-based optimization engine,
drag-and-drop specialization ranking (with touch/arrow support),
course selection UI, results dashboard with decision tree, and
two optimization modes (maximize-count, priority-order).

app/src/workers/decisionTree.worker.ts

@@ -0,0 +1,36 @@
+import { analyzeDecisionTree } from '../solver/decisionTree';
+import type { OptimizationMode } from '../data/types';
+import type { SetAnalysis } from '../solver/decisionTree';
+
+export interface WorkerRequest {
+  pinnedCourseIds: string[];
+  openSetIds: string[];
+  ranking: string[];
+  mode: OptimizationMode;
+}
+
+export interface WorkerResponse {
+  type: 'setComplete' | 'allComplete';
+  analysis?: SetAnalysis;
+  analyses?: SetAnalysis[];
+}
+
+self.onmessage = (e: MessageEvent<WorkerRequest>) => {
+  const { pinnedCourseIds, openSetIds, ranking, mode } = e.data;
+
+  const analyses = analyzeDecisionTree(
+    pinnedCourseIds,
+    openSetIds,
+    ranking,
+    mode,
+    (analysis) => {
+      // Progressive update: send each set's results as they complete
+      const response: WorkerResponse = { type: 'setComplete', analysis };
+      self.postMessage(response);
+    },
+  );
+
+  // Final result with sorted analyses
+  const response: WorkerResponse = { type: 'allComplete', analyses };
+  self.postMessage(response);
+};