feat(domain): pure business logic for parsing, identity, slots, acquisition, paths, organize, download state (W1-2)

- release-parser: title/file/dir parsing with MP parity + deviations (airDate/issue,
  cut, release group suffix fallback, dir+file merge, safe episode offset)
- identity: title normalization (NFKC, trad->simp map, season suffix) and
  evidence-level candidate ranking (year tolerance ±1, no probabilities)
- slot: hard/soft/upgrade evaluation (missing vs unmet fields), state machine,
  movie/unit completion (season pack must be covered by actual file list)
- acquisition: new_title/catch_up/upgrade modes, priority order, budget,
  cache volume hard threshold with resume watermark (no double counting)
- path: immutable path bindings, restricted naming templates, sanitize,
  conflict detection, downloader<->host path mapping
- organize: planOrganize with sidecar pairing, sample exclusion, existing
  target policy, crossDevice marking, H&R -> conflict for move
- download-state: qB state mapping, completion, no-progress evidence

230 tests, ~97% statement coverage.

Co-Authored-By: Claude Fable 5.1 <[email protected]>

packages/domain/src/acquisition/budget.ts

@@ -0,0 +1,59 @@
+export interface AcquisitionBudget {
+  maxNewTitlesPerDay?: number;
+  maxBytesPerDay?: number;
+  maxConcurrent?: number;
+}
+
+export interface BudgetUsage {
+  newTitlesToday: number;
+  bytesToday: number;
+  /** 已预留但尚未计入 bytesToday 的计划字节 */
+  reservedBytesToday?: number;
+  activeDownloads: number;
+}
+
+export interface BudgetRequest {
+  countsAsNewTitle: boolean;
+  bytes?: number;
+}
+
+export interface BudgetViolation {
+  kind: "new_titles" | "bytes" | "concurrency";
+  limit: number;
+  current: number;
+  requested: number;
+}
+
+export interface BudgetDecision {
+  decision: "allow" | "deny" | "unknown";
+  violations: BudgetViolation[];
+  /** 有字节预算但候选体积未知 */
+  unknown: "bytes"[];
+}
+
+/** 预算检查(每日新增作品数、下载字节、并发)。已知超限 → deny;体积未知 → unknown(不放行) */
+export function checkBudget(budget: AcquisitionBudget, usage: BudgetUsage, req: BudgetRequest): BudgetDecision {
+  const violations: BudgetViolation[] = [];
+  const unknown: "bytes"[] = [];
+  if (
+    req.countsAsNewTitle &&
+    budget.maxNewTitlesPerDay !== undefined &&
+    usage.newTitlesToday + 1 > budget.maxNewTitlesPerDay
+  )
+    violations.push({
+      kind: "new_titles",
+      limit: budget.maxNewTitlesPerDay,
+      current: usage.newTitlesToday,
+      requested: 1,
+    });
+  if (budget.maxBytesPerDay !== undefined) {
+    const current = usage.bytesToday + (usage.reservedBytesToday ?? 0);
+    if (req.bytes === undefined) unknown.push("bytes");
+    else if (current + req.bytes > budget.maxBytesPerDay)
+      violations.push({ kind: "bytes", limit: budget.maxBytesPerDay, current, requested: req.bytes });
+  }
+  if (budget.maxConcurrent !== undefined && usage.activeDownloads + 1 > budget.maxConcurrent)
+    violations.push({ kind: "concurrency", limit: budget.maxConcurrent, current: usage.activeDownloads, requested: 1 });
+  const decision = violations.length > 0 ? "deny" : unknown.length > 0 ? "unknown" : "allow";
+  return { decision, violations, unknown };
+}