Add server routes for companies, approvals, costs, and dashboard

New routes: companies, approvals, costs, dashboard, authz. New
services: companies, approvals, costs, dashboard, heartbeat,
activity-log. Add auth middleware and structured error handling.
Expand existing agent and issue routes with richer CRUD operations.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

server/src/services/activity-log.ts

@@ -0,0 +1,26 @@
+import type { Db } from "@paperclip/db";
+import { activityLog } from "@paperclip/db";
+
+export interface LogActivityInput {
+  companyId: string;
+  actorType: "agent" | "user" | "system";
+  actorId: string;
+  action: string;
+  entityType: string;
+  entityId: string;
+  agentId?: string | null;
+  details?: Record<string, unknown> | null;
+}
+
+export async function logActivity(db: Db, input: LogActivityInput) {
+  await db.insert(activityLog).values({
+    companyId: input.companyId,
+    actorType: input.actorType,
+    actorId: input.actorId,
+    action: input.action,
+    entityType: input.entityType,
+    entityId: input.entityId,
+    agentId: input.agentId ?? null,
+    details: input.details ?? null,
+  });
+}