fix(credentials): address Wave 5 code review findings (RHOAIENG-55817)

- RoleBinding name now includes session SA name to prevent subject
  collision when concurrent sessions in the same project share a provider
  (was credential-token-reader-{provider}, now {session-sa}-credential-{provider})
- clear_runtime_credentials() now removes GOOGLE_APPLICATION_CREDENTIALS
  path in addition to the hardcoded workspace credentials path, preventing
  SA key files from leaking across turns when GOOGLE_APPLICATION_CREDENTIALS
  is set to a non-default path
- Simplified test_returns_empty_when_no_credential_id_for_provider to use
  monkeypatch instead of redundant nested patch.dict + pop pattern
- Updated control-plane-development.md to clarify that credential scope
  filtering is server-side (RBAC), not implemented in resolveCredentialIDs

🤖 Generated with [Claude Code](https://claude.ai/code)

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

Author: Ambient Code Bot

.claude/context/control-plane-development.md

@@ -82,7 +82,7 @@ The runner drains the agent's inbox before starting the Claude Code session. All
 
 ### Credential fetch (Wave 5)
 
-The CP resolves credentials for the session before pod creation. For each provider (github, gitlab, jira, google), it walks agent → project → global scope and takes the most specific matching credential. It then:
+The CP resolves credentials for the session before pod creation. It calls `sdk.Credentials().ListAll()` — the API server applies RBAC-scoped filtering server-side, returning only credentials visible to the session's service account. The CP takes the first credential per provider (first-match wins; ordering is server-determined). It then:
 
 1. Builds `CREDENTIAL_IDS` — a JSON map of `provider → credential_id` — and injects it into the runner pod env
 2. Grants `credential:token-reader` on each credential ID to the runner pod's service account

components/ambient-control-plane/internal/reconciler/kube_reconciler.go

@@ -647,7 +647,7 @@ func (r *SimpleKubeReconciler) resolveCredentialIDs(ctx context.Context, sdk *sd
 
 func (r *SimpleKubeReconciler) ensureCredentialRoleBindings(ctx context.Context, namespace, saName string, credentialIDs map[string]string) error {
 	for provider, credID := range credentialIDs {
-		name := fmt.Sprintf("credential-token-reader-%s", provider)
+		name := fmt.Sprintf("%s-credential-%s", saName, provider)
 		rb := &unstructured.Unstructured{
 			Object: map[string]interface{}{
 				"apiVersion": "rbac.authorization.k8s.io/v1",

components/runners/ambient-runner/ambient_runner/platform/auth.py

@@ -446,18 +446,25 @@ def clear_runtime_credentials() -> None:
         except OSError as e:
             logger.warning(f"Failed to remove token file {token_file}: {e}")
 
-    # Remove Google Workspace credential file if present (uses same hardcoded path as populate_runtime_credentials)
-    google_cred_file = _GOOGLE_WORKSPACE_CREDS_FILE
-    if google_cred_file.exists():
-        try:
-            google_cred_file.unlink()
-            cleared.append("google_workspace_credentials_file")
-            # Clean up empty parent dirs
-            cred_dir = google_cred_file.parent
-            if cred_dir.exists() and not any(cred_dir.iterdir()):
-                cred_dir.rmdir()
-        except OSError as e:
-            logger.warning(f"Failed to remove Google credential file: {e}")
+    # Remove Google credential files — both the default workspace path and any
+    # path set via GOOGLE_APPLICATION_CREDENTIALS (used for SA JSON in Wave 5).
+    google_cred_files = {_GOOGLE_WORKSPACE_CREDS_FILE}
+    gac_path = os.getenv("GOOGLE_APPLICATION_CREDENTIALS", "")
+    if gac_path:
+        google_cred_files.add(Path(gac_path))
+
+    for google_cred_file in google_cred_files:
+        if google_cred_file.exists():
+            try:
+                google_cred_file.unlink()
+                cleared.append(str(google_cred_file.name))
+                cred_dir = google_cred_file.parent
+                if cred_dir.exists() and not any(cred_dir.iterdir()):
+                    cred_dir.rmdir()
+            except OSError as e:
+                logger.warning(
+                    f"Failed to remove Google credential file {google_cred_file}: {e}"
+                )
 
     if cleared:
         logger.info(f"Cleared credentials: {', '.join(cleared)}")

components/runners/ambient-runner/tests/test_shared_session_credentials.py

@@ -361,20 +361,13 @@ async def test_omits_current_user_header_when_not_set(self):
             thread.join(timeout=2)
 
     @pytest.mark.asyncio
-    async def test_returns_empty_when_no_credential_id_for_provider(self):
+    async def test_returns_empty_when_no_credential_id_for_provider(self, monkeypatch):
         """Verify graceful skip when CREDENTIAL_IDS does not contain the requested provider."""
-        with patch.dict(
-            os.environ,
-            {
-                "BACKEND_API_URL": "http://127.0.0.1:1/api",
-                "CREDENTIAL_IDS": json.dumps({"gitlab": "some-id"}),
-            },
-            clear=False,
-        ):
-            os.environ.pop("CREDENTIAL_IDS", None)
-            with patch.dict(os.environ, {"CREDENTIAL_IDS": json.dumps({"gitlab": "some-id"})}):
-                ctx = _make_context(current_user_id="user-123")
-                result = await _fetch_credential(ctx, "github")
+        monkeypatch.setenv("BACKEND_API_URL", "http://127.0.0.1:1/api")
+        monkeypatch.setenv("CREDENTIAL_IDS", json.dumps({"gitlab": "some-id"}))
+
+        ctx = _make_context(current_user_id="user-123")
+        result = await _fetch_credential(ctx, "github")
 
         assert result == {}
 
@@ -442,12 +435,14 @@ def log_message(self, format, *args):
         )
         thread.start()
 
-        credential_ids = json.dumps({
-            "github": "cred-gh",
-            "google": "cred-google",
-            "jira": "cred-jira",
-            "gitlab": "cred-gl",
-        })
+        credential_ids = json.dumps(
+            {
+                "github": "cred-gh",
+                "google": "cred-google",
+                "jira": "cred-jira",
+                "gitlab": "cred-gl",
+            }
+        )
 
         try:
             with patch.dict(