feat(05-01): budget enforcement types, schemas, IPC channels, and database CRUD

- Add BudgetPolicyRecord, BudgetIncidentRecord, BudgetStatusSummary types
- Add 6 IPC channels for budget operations in contracts.ts
- Add Zod schemas for all budget payloads
- Add DesktopApi entries for budget methods
- Add database CRUD: saveBudgetPolicy, deleteBudgetPolicy, listBudgetPolicies,
  getBudgetPolicy, getActivePoliciesForRun, getSpentInWindow (cents aggregation),
  upsertBudgetIncident (D-08 dedup), resolveIncidentsForPolicy,
  resolveWarnIncidentsForPolicy, autoCloseExpiredIncidents
- Update recordRunCompletion to include project_id in cost_entries INSERT
- Add migration 18: convert agent budgetMonthlyUsd to budget_policies rows
- Add preload bridge stubs for budget IPC channels

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/preload/index.ts

@@ -95,6 +95,12 @@ const api: DesktopApi = {
   listAgentSkills: (companyId, agentId) =>
     ipcRenderer.invoke(IPC_CHANNELS.listAgentSkills, { companyId, agentId }),
   listWakeupRequests: (input) => ipcRenderer.invoke(IPC_CHANNELS.listWakeupRequests, input),
+  saveBudgetPolicy: (input) => ipcRenderer.invoke(IPC_CHANNELS.saveBudgetPolicy, input),
+  deleteBudgetPolicy: (input) => ipcRenderer.invoke(IPC_CHANNELS.deleteBudgetPolicy, input),
+  listBudgetPolicies: (companyId) => ipcRenderer.invoke(IPC_CHANNELS.listBudgetPolicies, companyId),
+  listBudgetIncidents: (input) => ipcRenderer.invoke(IPC_CHANNELS.listBudgetIncidents, input),
+  resolveBudgetIncident: (input) => ipcRenderer.invoke(IPC_CHANNELS.resolveBudgetIncident, input),
+  getBudgetStatus: (companyId) => ipcRenderer.invoke(IPC_CHANNELS.getBudgetStatus, companyId),
   recoveryRetry: (taskId: string, agentId: string, companyId: string) =>
     ipcRenderer.invoke("recovery:retry", { taskId, agentId, companyId }),
   recoveryDismiss: (taskId: string) =>