feat(orchestrator): add premade secret sources and YAML definitions

Add SecretSourceService with premade secret source integrations:
- aws-secrets-manager (with --query SecretString for direct value)
- aws-parameter-store (with --with-decryption)
- gcp-secret-manager (latest version)
- azure-key-vault (via $AZURE_VAULT_NAME env var)
- env (environment variables, no shell command needed)
- Custom commands (any string with {0} placeholder)
- YAML file definitions for custom sources

Add secretSource input that takes precedence over inputPullCommand.
Backward compatible — existing inputPullCommand behavior unchanged.

Closes #776

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

src/model/orchestrator/options/orchestrator-options.ts

@@ -190,6 +190,10 @@ class OrchestratorOptions {
     return OrchestratorOptions.getInput('pullInputList')?.split(`,`) || [];
   }
 
+  static get secretSource(): string {
+    return OrchestratorOptions.getInput('secretSource') || '';
+  }
+
   static get inputPullCommand(): string {
     const value = OrchestratorOptions.getInput('inputPullCommand');