Promote AgentCompany-New to the repository root and retire the old app

The legacy application - its src, tests, landing site, promo assets, docs,
release tooling, CI workflows, and root configs - leaves the tree; it stays
reachable in history. Everything under AgentCompany-New moves up unchanged:
same package name, so the production userData/database path is untouched,
and e2e/build scripts already resolved paths relative to the project. The
developer cred.txt stays gitignored at its new location. Full verify:ci
passes from the new root.

src/shared/provider-runtime-domain.ts

@@ -0,0 +1,36 @@
+export interface ProviderRateLimitStateRecord {
+  orgId: string;
+  providerId: string;
+  providerKey: string;
+  windowStart: string;
+  windowEnd: string;
+  monthlyRequestLimit: number;
+  requestCount: number;
+  inputCharCount: number;
+  outputCharCount: number;
+  remainingRequestCount: number;
+  exhausted: boolean;
+}
+
+export interface ProviderObservedRateLimitState {
+  requestLimit: number | null;
+  remainingRequests: number | null;
+  resetAt: string | null;
+  retryAfterMs: number | null;
+  rawStateJson: string;
+}
+
+export interface ProviderRateLimitObservationRecord extends ProviderObservedRateLimitState {
+  id: string;
+  orgId: string;
+  providerId: string;
+  providerKey: string;
+  model: string | null;
+  observedAt: string;
+}
+
+export function currentProviderUsageWindow(now = new Date()): { start: string; end: string } {
+  const start = new Date(Date.UTC(now.getUTCFullYear(), now.getUTCMonth(), 1));
+  const end = new Date(Date.UTC(now.getUTCFullYear(), now.getUTCMonth() + 1, 1));
+  return { start: start.toISOString(), end: end.toISOString() };
+}