feat(skills): audit scan results and block unroutable skills

src/audit/types.ts

@@ -3,6 +3,8 @@ export type AuditLevel = 'debug' | 'info' | 'warn' | 'error';
 export type AuditEventType =
   // Tool execution
   | 'tool.start' | 'tool.success' | 'tool.error' | 'tool.denied' | 'tool.approval'
+  // Skills scan
+  | 'skills.scan.pass' | 'skills.scan.fail'
   // Skills installer
   | 'skills.installer.execution_blocked' | 'skills.installer.command_result'
   // Session lifecycle
@@ -122,6 +124,16 @@ export interface SkillsInstallerCommandResultEvent {
   reason: string;
 }
 
+export interface SkillsScanEvent {
+  skill_name: string;
+  tier: 'bundled' | 'managed' | 'workspace' | 'unknown';
+  phase: 'load' | 'install';
+  ok: boolean;
+  error_count: number;
+  warn_count: number;
+  issue_codes: string[];
+}
+
 export interface SessionCreateEvent {
   session_id: string;
   frontend: string;