v1.1.0: Add cancelled course, duplicate prevention, and credit bar ticks

- Mark "Managing Growing Companies" as cancelled with visual indicator and solver exclusion
- Prevent selecting duplicate courses across elective sets (e.g., same course in Spring and Summer)
- Add 2.5-credit interval tick marks to specialization progress bars
- Bump version to 1.1.0 with date display in UI header

app/src/solver/decisionTree.ts

@@ -30,13 +30,14 @@ function computeCeiling(
   otherOpenSetIds: string[],
   ranking: string[],
   mode: OptimizationMode,
+  excludedCourseIds?: Set<string>,
 ): { count: number; specs: string[] } {
   const fn = mode === 'maximize-count' ? maximizeCount : priorityOrder;
 
   if (otherOpenSetIds.length === 0) {
     // No other open sets — just solve with this choice added
     const selected = [...basePinnedCourses, chosenCourseId];
-    const result = fn(selected, ranking, []);
+    const result = fn(selected, ranking, [], excludedCourseIds);
     return { count: result.achieved.length, specs: result.achieved };
   }
 
@@ -50,7 +51,7 @@ function computeCeiling(
 
     if (setIndex >= otherOpenSetIds.length) {
       const selected = [...basePinnedCourses, chosenCourseId, ...accumulated];
-      const result = fn(selected, ranking, []);
+      const result = fn(selected, ranking, [], excludedCourseIds);
       if (result.achieved.length > bestCount) {
         bestCount = result.achieved.length;
         bestSpecs = result.achieved;
@@ -61,6 +62,7 @@ function computeCeiling(
     const setId = otherOpenSetIds[setIndex];
     const courses = coursesBySet[setId];
     for (const course of courses) {
+      if (excludedCourseIds?.has(course.id)) continue;
       enumerate(setIndex + 1, [...accumulated, course.id]);
       if (bestCount >= 3) return;
     }
@@ -91,6 +93,7 @@ export function analyzeDecisionTree(
   ranking: string[],
   mode: OptimizationMode,
   onSetComplete?: (analysis: SetAnalysis) => void,
+  excludedCourseIds?: Set<string>,
 ): SetAnalysis[] {
   if (openSetIds.length > MAX_OPEN_SETS_FOR_ENUMERATION) {
     // Fallback: return empty analyses (caller uses upper bounds instead)
@@ -107,21 +110,24 @@ export function analyzeDecisionTree(
     const otherOpenSets = openSetIds.filter((id) => id !== setId);
     const courses = coursesBySet[setId];
 
-    const choices: ChoiceOutcome[] = courses.map((course) => {
-      const ceiling = computeCeiling(
-        pinnedCourseIds,
-        course.id,
-        otherOpenSets,
-        ranking,
-        mode,
-      );
-      return {
-        courseId: course.id,
-        courseName: course.name,
-        ceilingCount: ceiling.count,
-        ceilingSpecs: ceiling.specs,
-      };
-    });
+    const choices: ChoiceOutcome[] = courses
+      .filter((course) => !excludedCourseIds?.has(course.id))
+      .map((course) => {
+        const ceiling = computeCeiling(
+          pinnedCourseIds,
+          course.id,
+          otherOpenSets,
+          ranking,
+          mode,
+          excludedCourseIds,
+        );
+        return {
+          courseId: course.id,
+          courseName: course.name,
+          ceilingCount: ceiling.count,
+          ceilingSpecs: ceiling.specs,
+        };
+      });
 
     const impact = variance(choices.map((c) => c.ceilingCount));
     const analysis: SetAnalysis = { setId, setName: set.name, impact, choices };