v1.3.1: Exhaustive decision-tree search + UX refinements

The v1.3.0 saturation termination silently capped the search after only
the heuristic-favored part of the tree, leaving most per-set ceiling cells
stuck at "0 specs" and hiding genuinely-feasible 3-spec plans in
maximize-count mode. Replace with full exhaustive enumeration plus a
batch of UX refinements that emerged during testing.

Algorithm:

- Drop the saturation early-termination entirely. Search now runs the
  full open-set cartesian product to completion; the iteration cap is
  also removed so no scenario exits partial.
- Add mode-dependent DFS child ordering: priority-order keeps the
  priority-target-first heuristic; maximize-count orders children by
  descending count of qualifications for reachable specs (generalist
  courses tried first).
- Make the (count, priorityScore) comparator mode-aware: priority-order
  ranks by (priorityScore, count) so the user's top spec surfaces;
  maximize-count ranks by (count, priorityScore) so the highest count
  wins. The same rule drives both top-K position and per-cell ceiling
  selection (and the Recommended badge).
- Add an evaluated boolean to each ChoiceOutcome and set it on first
  leaf evaluation. Distinguishes "still searching" from "evaluated, no
  specs achieved" so the UI never shows misleading 0 specs for a cell
  the search hasn't reached yet.
- Throttled progress events (~100ms) carrying iterations / total leaf
  count, drive both the per-set spinner and the global progress bar.

UI:

- Top Plans header shows a horizontal progress bar with
  "iterations / total · NN%" while the search runs; collapses to
  "Search complete · N explored" on completion.
- Per-set spinner next to each elective set heading while any choice
  in that set is unevaluated.
- Per-cell pulsing dot + "searching" text for unevaluated cells.
- Replace the "(HCR, BNK, ...)" text labels on each course with
  color-coded SpecTag pills using a new fixed per-spec palette
  (app/src/data/specColors.ts). Same palette applied to the Top Plans
  achievement badges so the two views are visually consistent.
- "Top outcome if picked ↓" caption above the right side of each open
  elective set so the spec tags are clearly identified as decision-tree
  outcomes (not the course's own qualifications).
- Recommended badge moved inline next to the course name (instead of
  on a separate row below) to keep button heights stable.

Tests:

- Replace the saturation early-termination test with an exhaustion test
  asserting every cell ends with evaluated: true and partial: false.
- Add mode-dependent ordering test (max-count visits Climate Finance
  before Corporate Governance in fall3).
- Add evaluated-flag transition test.
- Add throttled progress-event test (>= ~100ms between consecutive
  emits).
- Performance smoke updated to a 60s budget for the exhaustive
  user-scenario search; 8-open-set typical case completes in ~7s.

Files: solver/decisionTree.ts, solver/priority.ts (already shipped),
data/specColors.ts (new), components/{TopPlans,CourseSelection}.tsx,
state/appState.ts, workers/decisionTree.worker.ts,
__tests__/searchDecisionTree.test.ts, vite.config.ts, CHANGELOG.md,
openspec/changes/decision-tree-exhaustive-search/* (full change spec).

CHANGELOG.md

@@ -1,5 +1,19 @@
 # Changelog
 
+## v1.3.1 — 2026-05-09
+
+### Changes
+
+- **Exhaustive decision-tree search** — replaced the saturation early-termination with full enumeration of the open-set cartesian product. Per-set ceiling cells now reflect the true best outcome for every (set, course) pair instead of leaving most cells stuck at "0 specs". Top Plans surfaces all genuinely-feasible plans, including 3-spec maximize-count plans that the v1.3.0 search missed. The previous iteration cap has been removed; search runs to full completion.
+- **Mode-dependent enumeration ordering** — priority-order mode keeps the priority-target-first heuristic; maximize-count mode now orders DFS children by descending count of qualifications for *reachable* specializations, surfacing generalist courses (e.g., Climate Finance with 6 qualifications) before specialists.
+- **Mode-aware comparator** — top-K and per-cell ceiling rankings now match the active mode: priority-order ranks by `(priorityScore, count)` so the top-priority spec surfaces; maximize-count ranks by `(count, priorityScore)` so the highest count wins. Recommended badges follow the same rule.
+- **"Recommended" badge per set** — each elective set now highlights the choice with the best ceiling outcome under the current mode. Rendered inline next to the course name to keep button height stable.
+- **Color-coded spec tags** — the per-cell outcome list and the Top Plans badges now use a fixed per-spec color palette so each specialization is visually identifiable at a glance.
+- **"Top outcome if picked ↓" caption** — added a small column header on each open elective set so the spec tags are clearly identified as decision-tree outcomes (not the course's own qualifications).
+- **Visual progress bar** — Top Plans header now shows a progress bar with `iterations / total · NN%` while the search runs, replacing the earlier text-only count.
+- **Per-cell streaming indicators** — courses that haven't been evaluated yet show a "searching" pulse instead of misleading "0 specs"; cells transition to their final value as the search completes.
+- **Per-set spinner** — each elective set heading shows a spinner while at least one of its choices is still unevaluated.
+
 ## v1.3.0 — 2026-05-09
 
 ### Changes