refactor(contracts): split schemas-misc into per-domain files

Break the 281-line kitchen-sink schemas-misc.ts into 12 domain modules
(badges, automation, budget, wakeup, config-revisions, run-events,
agent-permissions, heartbeat, runtime-state, threads, participants,
subscriptions). schemas-misc.ts now re-exports the domain barrel so
existing imports keep working. Adds direct exports to contracts.ts for
new code to pull from the narrower modules.

src/shared/contracts/schemas-agent-permissions.ts

@@ -0,0 +1,12 @@
+import { z } from "zod";
+
+export const getAgentPermissionsSchema = z.object({
+  agentId: z.string().min(1),
+});
+
+export const setAgentPermissionSchema = z.object({
+  companyId: z.string().min(1),
+  agentId: z.string().min(1),
+  permissionKey: z.string().min(1),
+  enabled: z.boolean(),
+});