fix(backend): move CLAUDE_CODE_DISABLE_EXPERIMENTAL_BETAS into build_sdk_env

Moves the env var injection from service.py into build_sdk_env() in
env.py so all callers (including orchestrator.py) get it automatically.
Also changes xfail(strict=False) to strict=True so CI fails if the
upstream fix lands and we can remove the workaround.

autogpt_platform/backend/backend/copilot/sdk/cli_openrouter_compat_test.py

@@ -460,7 +460,7 @@ def _assert_no_forbidden_patterns(
     "CLAUDE_CODE_DISABLE_EXPERIMENTAL_BETAS=1. This is expected — the env "
     "var guard in test_disable_experimental_betas_env_var_strips_headers "
     "is the real regression test.",
-    strict=False,
+    strict=True,
 )
 async def test_bare_cli_does_not_send_openrouter_incompatible_features():
     """Bare CLI reproduction (no env var workaround).

autogpt_platform/backend/backend/copilot/sdk/env.py

@@ -96,5 +96,8 @@ def build_sdk_env(
     env["CLAUDE_CODE_DISABLE_CLAUDE_MDS"] = "1"
     env["CLAUDE_CODE_DISABLE_AUTO_MEMORY"] = "1"
     env["CLAUDE_CODE_DISABLE_NONESSENTIAL_TRAFFIC"] = "1"
+    # Strip Anthropic-specific beta headers (e.g. context-management-2025-06-27)
+    # that OpenRouter rejects.  Safe for all modes — direct Anthropic ignores it.
+    env["CLAUDE_CODE_DISABLE_EXPERIMENTAL_BETAS"] = "1"
 
     return env

autogpt_platform/backend/backend/copilot/sdk/service.py

@@ -2242,15 +2242,6 @@ async def stream_chat_completion_sdk(
         if sdk_model:
             sdk_options_kwargs["model"] = sdk_model
 
-        # Tell the CLI to strip experimental betas (e.g.
-        # ``context-management-2025-06-27``) and ``tool_reference``
-        # content blocks so newer SDK / CLI versions work with
-        # OpenRouter's stricter validation.  This single env var
-        # replaces the old in-process compat proxy.
-        if sdk_env is None:
-            sdk_env = {}
-        sdk_env["CLAUDE_CODE_DISABLE_EXPERIMENTAL_BETAS"] = "1"
-
         if sdk_env:
             sdk_options_kwargs["env"] = sdk_env
         if use_resume and resume_file: