refactor: return a single bool from _repair_transport_credentials

Both callers immediately reduced the (headers_sanitized, credential_sanitized)
tuple with `or`; nobody distinguished the two. Returning one
`transport_repaired` bool removes the unpacking at both call sites and the
redundant flag bookkeeping inside the helper without changing behaviour.

agent/turn_recovery.py

@@ -111,19 +111,18 @@ def _try_refresh_nous_paid_entitlement_credentials(agent) -> bool:
         return False
 
 
-def _repair_transport_credentials(agent: Any) -> Tuple[bool, bool]:
+def _repair_transport_credentials(agent: Any) -> bool:
     """Strip non-ASCII from ``_client_kwargs["default_headers"]`` and the API key.
 
     Non-ASCII in the key makes httpx fail encoding the Authorization header — the usual
     persistent cause of UnicodeEncodeError that survives message/tool sanitization (#6843,
     e.g. ʋ instead of v from a bad copy-paste). Entra ID bearer providers are callables
-    minting ASCII JWTs; skip them (``_strip_non_ascii`` would crash). Returns
-    ``(headers_sanitized, credential_sanitized)``.
+    minting ASCII JWTs; skip them (``_strip_non_ascii`` would crash). Returns True when
+    either the headers or the key were repaired.
     """
     _client_kwargs = getattr(agent, "_client_kwargs", None)
     _default_headers = _client_kwargs.get("default_headers") if isinstance(_client_kwargs, dict) else None
-    _headers_sanitized = bool(isinstance(_default_headers, dict) and _sanitize_structure_non_ascii(_default_headers))
-    _credential_sanitized = False
+    _repaired = bool(isinstance(_default_headers, dict) and _sanitize_structure_non_ascii(_default_headers))
     _raw_key = getattr(agent, "api_key", None) or ""
     if isinstance(_raw_key, str) and _raw_key:
         _clean_key = _strip_non_ascii(_raw_key)
@@ -134,13 +133,13 @@ def _repair_transport_credentials(agent: Any) -> Tuple[bool, bool]:
             # The live client reads its own api_key copy on every request.
             if getattr(agent, "client", None) is not None and hasattr(agent.client, "api_key"):
                 agent.client.api_key = _clean_key
-            _credential_sanitized = True
+            _repaired = True
             _vlines(
                 agent,
                 "⚠️  API key contained non-ASCII characters (bad copy-paste?) — stripped them. "
                 "If auth fails, re-copy the key from your provider's dashboard.",
             )
-    return _headers_sanitized, _credential_sanitized
+    return _repaired
 
 
 def _recover_unicode_encode_error(
@@ -183,8 +182,7 @@ def _recover_unicode_encode_error(
     # succeed — return False so the error surfaces through the normal path
     # instead of burning both sanitization passes on unchanged requests.
     if not _runtime_uses_ascii_encoding():
-        _headers_sanitized, _credential_sanitized = _repair_transport_credentials(agent)
-        if not (_headers_sanitized or _credential_sanitized):
+        if not _repair_transport_credentials(agent):
             return False, active_system_prompt
         agent._unicode_sanitization_passes += 1
         _vlines(
@@ -207,7 +205,7 @@ def _recover_unicode_encode_error(
             active_system_prompt = _sanitized_system
             _system_sanitized = True
 
-    _headers_sanitized, _credential_sanitized = _repair_transport_credentials(agent)
+    _transport_repaired = _repair_transport_credentials(agent)
 
     # Always retry on ASCII codec detection: _force_ascii_payload sanitizes the full
     # api_kwargs next iteration even when the checks above find nothing.
@@ -215,8 +213,7 @@ def _recover_unicode_encode_error(
     _vlines(
         agent,
         "⚠️  System encoding is ASCII — stripped non-ASCII characters from request payload. Retrying..."
-        if (_messages_sanitized or _system_sanitized
-            or _headers_sanitized or _credential_sanitized) else
+        if (_messages_sanitized or _system_sanitized or _transport_repaired) else
         "⚠️  System encoding is ASCII — enabling full-payload sanitization for retry...",
     )
     return True, active_system_prompt