feat: 研究规则 rules 模块（任务书 02）

rules 是纯计算，src/rules 共 1761 行：方法.md 第六部分的全部公式、第七部分的余额与扣次、4.2 的入口分配，以及种子与规则登记表。

预期值有三个来源：方法.md 的手算例；tests/fixtures/rules/ 下不看实现写的 Python 脚本；参考项目 calc15、calc14b 里与现行方法一致的部分。审阅做了两轮，每轮都换一个全新上下文的子 Agent，提出的问题都已修复或写明不修的理由。

用户确认的约定（原话"1–8 都同意"）：入池、采纳、消融中发现都用严格不等号；成本用 max(0, ĝ₀)；没测的格附"含它的最好组合"的净值；战绩在分数原值上判。三个数改为严格递增后，删掉了尖峰的全部专门处理（bfb96ba）。vocab 里 Range 的说明同步改为严格递增。

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/rules/index.ts

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+// rules：方法.md 第六部分的全部公式和常数、第七部分的余额、4.2 的入口分配（docs/结构.md 第二部分）。
+// 纯计算：输入数字，输出数字，不碰文件、数据库、模型，也不用全局随机数。
+export {
+  combinations,
+  compareIds,
+  epsilonFloor,
+  GRID_COMBINATION_CAP,
+  GRID_SUBDIVISIONS,
+  improvement,
+  INDISPENSABLE_SUPPORT,
+  INTERACTION_CUT,
+  NET_TOLERANCE,
+} from "./basics.ts";
+export {
+  ablationCellMixture,
+  authorShares,
+  below,
+  breakpoints,
+  density,
+  forwardMergedRange,
+  forwardMixtures,
+  integrateUpperTail,
+  knotsMean,
+  mapKnots,
+  mapMixture,
+  mixtureBelow,
+  mixtureQuantile,
+  mixtureRange,
+  personKnots,
+  reserveKnots,
+  toImprovement,
+  type Component,
+  type Knots,
+  type Mixture,
+  type Point,
+} from "./distribution.ts";
+export {
+  adopt,
+  adoptionLine,
+  batchValue,
+  lossProbability,
+  selectBestExpected,
+  selectUniformRandom,
+  type AdoptionLineInput,
+  type BatchDecision,
+  type BatchInput,
+} from "./forward.ts";
+export {
+  ablationFinding,
+  inseparableGroups,
+  judgeExplanations,
+  listCells,
+  settleAblation,
+  sharedSettings,
+  supportOf,
+  synergyLabel,
+  totalGain,
+  type AblationCell,
+  type AblationExplanation,
+  type CellOutcome,
+  type SettleInput,
+  type SynergyLabel,
+  type ExplanationVerdict,
+} from "./ablation.ts";
+export {
+  ablationModel,
+  cellGrid,
+  evaluateCombos,
+  gridSize,
+  informationValue,
+  informationValueExact,
+  informationValueGrid,
+  measuredGrid,
+  OPEN_RESERVE,
+  remainingSpace,
+  type AblationModel,
+  type AblationModelInput,
+  type ComboParams,
+  type ComboValue,
+} from "./value.ts";
+export {
+  chooseBet,
+  pickByNet,
+  selectAll,
+  selectByValue,
+  selectNone,
+  selectRandomSameCount,
+  topCombo,
+  type BetResult,
+  type CellDecision,
+  type CellRuleInput,
+  type UntestedReason,
+} from "./cells.ts";
+export {
+  bitWidth,
+  cellIndex,
+  coverage,
+  covers,
+  disagreement,
+  entropyBits,
+  placement,
+  surprise,
+  worldBits,
+  type Placement,
+} from "./bits.ts";
+export { ablationCellLimit, forwardBatchSize, runBalance, type RunState } from "./budget.ts";
+export { authorVsMerged, trackRecord, type Phase, type Tally } from "./record.ts";
+export { assignEntries, type EntryAssignment } from "./entries.ts";
+export { decisionSeed, seededRandom, seededSample } from "./random.ts";
+export {
+  BATCH_RULES,
+  CELL_RULES,
+  runBatchRule,
+  runCellRule,
+  type BatchRuleName,
+  type CellRuleName,
+} from "./registry.ts";