docs: add source-provenance comment to secret-distribution (card [91] backfill 2/16)

docs/secret-distribution.md

@@ -1,3 +1,9 @@
+<!-- verified: 2026-09-06
+     iac@49ff427 : ansible/roles/secure_vault/ssh_ca_client, ansible/roles/secure_vault/vault_agent/defaults/main.yml, ansible/roles/secure_vault/SecureVault – Vault Contract.md, ansible/roles/secure_vault/securevault-vault-facts.md
+     ansible@ccbda37 : roles/app_update/defaults/main.yml
+     trilium : DvKxK0gHXsng, wovVrgvoDVy2, GW8BMoTKtRBe, 1seDR2nBmxKO
+-->
+
 # 🔑 Secret Distribution Model
 
 > [!NOTE]