feat(Bug): 状态流转接入单条工作流

apps/web/lib/bug-workflow.ts

@@ -0,0 +1,62 @@
+import type { Bug, BugLog, BugStatus } from './bug';
+import { canBugTransition } from './bug';
+
+export interface BugTransitionOptions {
+  now?: Date;
+  resolution?: string;
+}
+
+export interface BugWorkflowResult {
+  ok: boolean;
+  patch?: Partial<Bug>;
+  message?: string;
+}
+
+function makeBugLog(
+  action: BugLog['action'],
+  operator: string,
+  nowIso: string,
+  from?: string,
+  to?: string,
+  remark?: string,
+): BugLog {
+  return {
+    id: `log-${Date.now()}-${Math.random().toString(36).slice(2, 6)}`,
+    action,
+    fromValue: from,
+    toValue: to,
+    operator,
+    remark,
+    createdAt: nowIso,
+  };
+}
+
+export function applyBugTransition(
+  bug: Bug,
+  to: BugStatus,
+  operator: string,
+  options: BugTransitionOptions = {},
+): BugWorkflowResult {
+  if (!canBugTransition(bug.status, to)) {
+    return { ok: false, message: `不允许从「${bug.status}」流转到「${to}」` };
+  }
+
+  const nowIso = (options.now ?? new Date()).toISOString();
+  const patch: Partial<Bug> = { status: to };
+
+  if (to === 'fixed') patch.resolvedAt = nowIso;
+  if (to === 'closed') patch.closedAt = nowIso;
+  if (options.resolution?.trim()) patch.resolution = options.resolution.trim();
+
+  const log = makeBugLog(
+    to === 'fixed' ? 'resolve' : 'status_change',
+    operator,
+    nowIso,
+    bug.status,
+    to,
+    options.resolution,
+  );
+  patch.logs = [...(bug.logs || []), log];
+
+  return { ok: true, patch };
+}