feat(policy): enforce truthfulness and autonomy guardrails

Add runtime truthfulness modes and autonomy-level tool gating with audit metadata for overrides/denials.

Wire policy through prompt assembly, tool execution context, and daemon/gateway agent paths; update tests and planning state for Phase 3 PR #2 completion.

src/audit/types.ts

@@ -1,6 +1,6 @@
 export type AuditLevel = 'debug' | 'info' | 'warn' | 'error';
 
-export type AuditEventType = 
+export type AuditEventType =
   // Tool execution
   | 'tool.start' | 'tool.success' | 'tool.error' | 'tool.denied'
   // Session lifecycle
@@ -72,7 +72,7 @@ export interface ToolDeniedEvent {
   tool_name: string;
   reason: string;
   session_id?: string;
-  denial_type: 'policy' | 'hook' | 'not_found';
+  denial_type: 'policy' | 'hook' | 'not_found' | 'autonomy_override';
 }
 
 export interface SessionCreateEvent {