v1.3.0: Streamed top-K decision-tree plans + priority-aware ceiling

Fixes the bug where a specialization could show "Achievable" while no
per-set ceiling cell surfaces a path to it. Reproduction: pin SP2=Business
of Health & Medical Care, SP4=Foundations of Fintech, SP5=Corporate Finance,
SE1=GIE; rank HCR first. Healthcare showed Achievable but every ceiling
cell excluded HCR.

Root cause: computeCeiling used strict > on count alone, so the first
equal-count combination found won permanently and HCR-including outcomes
were never recorded.

Changes:

- Replace per-(set, choice) computeCeiling loop with a single full-tree
  searchDecisionTree DFS. Both the per-set ceiling table and a new ranked
  top-K plan list (default K=10) are populated from one enumeration.
- Comparison rule everywhere is (count desc, priority score desc,
  deterministic-tiebreak). priorityScore extracted from optimizer.ts
  into a shared priority.ts module used by both call sites.
- Heuristic enumeration ordering: select the first reachable ranked spec
  as priorityTarget; reorder DFS children at every level so target-
  qualifying courses are tried first. High-priority outcomes surface in
  early iterations instead of being blocked by less-relevant equal-count
  results.
- Bounded search: terminate on saturation (top-K stable for 500
  iterations) or hard cap (10000 iterations); set partial=true if cap
  hit. Mitigates the worst-case enumeration cost.
- Worker protocol: tagged-union response with topKUpdate, choiceUpdate
  (per-cell, replaces per-set setComplete), and allComplete events.
- App state adds topPlans/topPlansPartial slices and an adoptPlan action
  that pins a plan's full course assignment in one click. Also fixes
  loadState's stale "ranking.length !== 14" check (now uses
  SPECIALIZATIONS.length so HCR-era saved state restores correctly).
- New TopPlans component renders the ranked list with adopt buttons,
  placed above CourseSelection in the right column.
- 17 new tests in searchDecisionTree.test.ts covering priority scoring,
  bounded ranked list, comparison rule, target selection, the user's
  reproduction scenario, streaming monotonicity, saturation termination,
  and a performance smoke test (< 5s for the 8-open-set case).
- Existing decisionTree.test.ts: one test amended for per-cell streaming
  semantics; remaining 3 unchanged and passing.

CHANGELOG.md

@@ -1,5 +1,14 @@
 # Changelog
 
+## v1.3.0 — 2026-05-09
+
+### Changes
+
+- **Top Plans panel** — new ranked list of up to 10 complete course plans, each showing the achieved specializations and the courses to pin. An "Adopt plan" button pins all of a plan's courses in one click. Updates progressively as the search finds better outcomes.
+- **Priority-aware decision tree** — fixes the bug where a specialization could show "Achievable" without any per-set ceiling cell surfacing it. The decision-tree search now compares enumerated combinations by `(count desc, priority score desc)` and reorders DFS children so courses qualifying for the user's first reachable ranked spec are tried first, surfacing high-priority outcomes early.
+- **Bounded search with saturation termination** — search stops when the top-K stabilizes (default 500 stable iterations) or when the iteration cap (10000) is hit; partial results are flagged in the UI.
+- **Per-cell streaming** — the worker now emits per-cell ceiling updates instead of per-set rollups, so the per-set table refines progressively rather than appearing in coarse chunks.
+
 ## v1.2.2 — 2026-05-09
 
 ### Changes