feat(routing): add routing_rules schema, condition types, and action types (M4-001/002/003)

- Add routing_rules table to packages/db with scope, priority, conditions (jsonb), and action (jsonb) columns; generate migration 0004
- Define RoutingCondition, RoutingAction, RoutingRule, TaskClassification, and RoutingDecision types in apps/gateway/src/agent/routing/routing.types.ts
- Expand @mosaic/types routing/index.ts to export all M4 types (TaskType, Complexity, Domain, CostTier+local, Capability) alongside existing RoutingCriteria/RoutingResult
- Fix pre-existing type errors in routing.service.ts (local CostTier) and default-rules.ts (count optional chaining, unknown cast)
- Fix pre-existing Prettier violations in agent module and provider files

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

apps/gateway/src/agent/agent.module.ts

@@ -1,6 +1,7 @@
 import { Global, Module } from '@nestjs/common';
 import { AgentService } from './agent.service.js';
 import { ProviderService } from './provider.service.js';
+import { ProviderCredentialsService } from './provider-credentials.service.js';
 import { RoutingService } from './routing.service.js';
 import { SkillLoaderService } from './skill-loader.service.js';
 import { ProvidersController } from './providers.controller.js';
@@ -14,8 +15,20 @@ import { GCModule } from '../gc/gc.module.js';
 @Global()
 @Module({
   imports: [CoordModule, McpClientModule, SkillsModule, GCModule],
-  providers: [ProviderService, RoutingService, SkillLoaderService, AgentService],
+  providers: [
+    ProviderService,
+    ProviderCredentialsService,
+    RoutingService,
+    SkillLoaderService,
+    AgentService,
+  ],
   controllers: [ProvidersController, SessionsController, AgentConfigsController],
-  exports: [AgentService, ProviderService, RoutingService, SkillLoaderService],
+  exports: [
+    AgentService,
+    ProviderService,
+    ProviderCredentialsService,
+    RoutingService,
+    SkillLoaderService,
+  ],
 })
 export class AgentModule {}