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/main/services/provider-response-observer.ts

@@ -0,0 +1,114 @@
+import type { DatabaseSync } from "node:sqlite";
+import { SLO_SIGNAL_KEY, type ProviderExecutionMode } from "../../shared/domain";
+import type { ProviderObservedRateLimitState } from "../../shared/provider-runtime-domain";
+import { AuditService } from "./audit-service";
+import { OperationsService } from "./operations-service";
+import { providerRateLimitStateFromError } from "./provider-adapters";
+import { ProviderRateLimitRegistry } from "./provider-rate-limit-registry";
+import { ProviderRequestStore } from "./provider-request-store";
+
+const HEALTH_STATE_HEALTHY = "healthy";
+const HEALTH_STATE_FAILED = "failed";
+
+export interface ProviderResponseObserverProvider {
+  id: string;
+  provider_key: string;
+  model: string | null;
+}
+
+export interface ProviderResponseSuccessInput {
+  orgId: string;
+  provider: ProviderResponseObserverProvider;
+  requestId: string;
+  executionMode: ProviderExecutionMode;
+  startedAt: number;
+  action: "response_created" | "response_streamed" | "background_response_completed";
+}
+
+export interface ProviderResponseFailureInput {
+  orgId: string;
+  provider: ProviderResponseObserverProvider;
+  requestId: string;
+  executionMode: ProviderExecutionMode;
+  startedAt: number;
+  inputCharCount: number;
+  error: unknown;
+  rawResponseJson?: string | null;
+}
+
+export class ProviderResponseObserver {
+  constructor(
+    private readonly db: DatabaseSync,
+    private readonly audit: AuditService,
+    private readonly operations: OperationsService,
+    private readonly requestStore: ProviderRequestStore,
+    private readonly rateLimitRegistry: ProviderRateLimitRegistry,
+  ) {}
+
+  recordSuccess(input: ProviderResponseSuccessInput): void {
+    this.recordProviderHealth(input.provider.id, input.orgId, HEALTH_STATE_HEALTHY, null);
+    this.audit.record({
+      orgId: input.orgId,
+      entityType: "provider_request",
+      entityId: input.requestId,
+      actorType: "system",
+      actorId: null,
+      action: input.action,
+      payload: { providerKey: input.provider.provider_key, model: input.provider.model },
+    });
+    this.operations.recordSignal({
+      orgId: input.orgId,
+      signalKey: SLO_SIGNAL_KEY.PROVIDER_REQUEST_SUCCESS,
+      source: "provider_gateway",
+      success: true,
+      durationMs: Date.now() - input.startedAt,
+      detail: { requestId: input.requestId, providerKey: input.provider.provider_key, executionMode: input.executionMode },
+    });
+  }
+
+  recordFailure(input: ProviderResponseFailureInput): void {
+    const message = input.error instanceof Error ? input.error.message : String(input.error);
+    this.recordObservedRateLimit(input.orgId, input.provider, input.provider.model, providerRateLimitStateFromError(input.error));
+    this.requestStore.markFailed({
+      orgId: input.orgId,
+      requestId: input.requestId,
+      errorMessage: message,
+      completedAt: new Date().toISOString(),
+      rawResponseJson: input.rawResponseJson,
+    });
+    this.requestStore.recordUsage(input.orgId, input.provider.id, input.inputCharCount, 0);
+    this.recordProviderHealth(input.provider.id, input.orgId, HEALTH_STATE_FAILED, message);
+    this.operations.recordSignal({
+      orgId: input.orgId,
+      signalKey: SLO_SIGNAL_KEY.PROVIDER_REQUEST_SUCCESS,
+      source: "provider_gateway",
+      success: false,
+      durationMs: Date.now() - input.startedAt,
+      detail: { requestId: input.requestId, providerKey: input.provider.provider_key, executionMode: input.executionMode },
+    });
+  }
+
+  recordObservedRateLimit(
+    orgId: string,
+    provider: ProviderResponseObserverProvider,
+    model: string | null,
+    state: ProviderObservedRateLimitState | null,
+  ): void {
+    if (!state) return;
+    this.rateLimitRegistry.recordObservation({
+      orgId,
+      providerId: provider.id,
+      providerKey: provider.provider_key,
+      model,
+      state,
+    });
+  }
+
+  private recordProviderHealth(providerId: string, orgId: string, healthState: string, error: string | null): void {
+    this.db.prepare(`
+      update providers
+      set health_state = ?, last_error = ?, last_checked_at = ?
+      where id = ? and org_id = ?
+    `).run(healthState, error, new Date().toISOString(), providerId, orgId);
+  }
+}