fix(bird_x): pass .env credentials to Node subprocesses for WSL2/headless auth

* chore: fix YAML error in argument-hint

* add codex auth support to responses API

* Use gpt-5.1-codex-mini as default model for Codex auth

Add CODEX_FALLBACK_MODELS chain (gpt-5.1-codex-mini → gpt-5.2) for
Codex endpoint which doesn't support standard OpenAI models like
gpt-4o-mini. Adds model fallback retry on 400 errors in the Codex
search path. Also adds test_codex_auth.py with 22 unit tests covering
JWT decoding, auth resolution, SSE parsing, and payload building.

* Pass .env credentials to Bird Node subprocesses for X auth

On platforms without browser cookie access (e.g. WSL2), Bird's
vendored Node.js module cannot read AUTH_TOKEN/CT0 from Firefox
or Chrome cookie stores. The .env config file already supports
these values, but they were only loaded into the Python config
dict — never exported to the environment of Node subprocesses.

- Add AUTH_TOKEN/CT0 to env.py config key loading
- Add set_credentials()/\_subprocess_env() to bird_x.py to inject
  credentials into the env dict passed to subprocess.run/Popen
- Call set_credentials() in main() before Bird auth detection

---------

Co-authored-by: Justin Williams <jblwilliams@gmail.com>

scripts/last30days.py

@@ -111,7 +111,6 @@ from lib import (
     schema,
     score,
     ui,
-    websearch,
     xai_x,
     youtube_yt,
 )
@@ -154,6 +153,8 @@ def _search_reddit(
                 from_date,
                 to_date,
                 depth=depth,
+                auth_source=config.get("OPENAI_AUTH_SOURCE", "api_key"),
+                account_id=config.get("OPENAI_CHATGPT_ACCOUNT_ID"),
             )
         except http.HTTPError as e:
             raw_openai = {"error": str(e)}
@@ -176,6 +177,8 @@ def _search_reddit(
                     core,
                     from_date, to_date,
                     depth=depth,
+                    auth_source=config.get("OPENAI_AUTH_SOURCE", "api_key"),
+                    account_id=config.get("OPENAI_CHATGPT_ACCOUNT_ID"),
                 )
                 retry_items = openai_reddit.parse_reddit_response(retry_raw)
                 # Add items not already found (by URL)
@@ -1032,6 +1035,9 @@ def main():
     # Load config
     config = env.get_config()
 
+    # Inject .env credentials into Bird module before auth check
+    bird_x.set_credentials(config.get('AUTH_TOKEN'), config.get('CT0'))
+
     # Auto-detect Bird (no prompts - just use it if available)
     x_source_status = env.get_x_source_status(config)
     x_source = x_source_status["source"]  # 'bird', 'xai', or None