fix(secrets): scope-aware Azure credential presence reads in identity diagnostics

AZURE_CLIENT_SECRET and AZURE_FEDERATED_TOKEN_FILE presence checks in the
Entra diagnostics path now read through the profile secret scope (Slack
pattern) instead of raw os.environ.

agent/azure_identity_adapter.py

@@ -367,11 +367,27 @@ def describe_active_credential(config: Optional[EntraIdentityConfig] = None,
         info["tenant_id_env"] = os.environ["AZURE_TENANT_ID"].strip()
 
     # Surface which env-var sources are present without minting yet.
+    # Credential-bearing vars (AZURE_CLIENT_SECRET, AZURE_FEDERATED_TOKEN_FILE)
+    # are read through the profile secret scope so a multiplexed profile's
+    # diagnostics don't report another profile's env-bridged credentials;
+    # unscoped CLI probes keep the legacy env read (Slack pattern).
+    def _scoped_env(name: str) -> str:
+        try:
+            from agent.secret_scope import UnscopedSecretError, get_secret
+
+            try:
+                return (get_secret(name) or "").strip()
+            except UnscopedSecretError:
+                pass
+        except Exception:
+            pass
+        return os.environ.get(name, "").strip()
+
     env_sources = []
-    if os.environ.get("AZURE_FEDERATED_TOKEN_FILE", "").strip():
+    if _scoped_env("AZURE_FEDERATED_TOKEN_FILE"):
         env_sources.append("WorkloadIdentityCredential (AZURE_FEDERATED_TOKEN_FILE)")
     if (os.environ.get("AZURE_CLIENT_ID", "").strip()
-            and os.environ.get("AZURE_CLIENT_SECRET", "").strip()
+            and _scoped_env("AZURE_CLIENT_SECRET")
             and os.environ.get("AZURE_TENANT_ID", "").strip()):
         env_sources.append("EnvironmentCredential (client secret)")
     if os.environ.get("IDENTITY_ENDPOINT", "").strip() or os.environ.get("MSI_ENDPOINT", "").strip():