fix(codex): resync pool entry from auth.json after reauth (#17001)

When openai-codex tokens expire or the ChatGPT account hits a 429
window, the pool entry gets marked STATUS_EXHAUSTED with
last_error_reset_at many hours in the future. If the user then runs
`hermes model` / `hermes auth openai-codex` to reauth, fresh tokens
land in ~/.hermes/auth.json but the pool entry stayed frozen behind
its reset_at — every request kept failing with 'credential pool: no
available entries (all exhausted or empty)' until the original window
elapsed.

_available_entries() already had auth.json/credentials-file resync
branches for anthropic/claude_code and nous/device_code; openai-codex
was missing. Added _sync_codex_entry_from_auth_store() mirroring the
nous version (reads state["tokens"][{access,refresh}_token] +
state["last_refresh"]) and wired it into the exhausted-entry resync
loop.

Also softens the 'codex CLI not found' doctor warning — native
device-code OAuth does not require the Codex binary, only
importing existing Codex CLI tokens does. Downgraded to an info line.

Reported on Discord by p1aceho1der: Codex stalled indefinitely after
a rate-limit reset, reauth didn't help, and doctor falsely warned
that the codex CLI was required.

Co-authored-by: teknium1 <teknium@users.noreply.github.com>

hermes_cli/doctor.py

@@ -517,7 +517,14 @@ def run_doctor(args):
     if shutil.which("codex"):
         check_ok("codex CLI")
     else:
-        check_warn("codex CLI not found", "(required for openai-codex login)")
+        # Native OAuth uses Hermes' own device-code flow — the Codex CLI is
+        # only needed if you want to import existing tokens from
+        # ~/.codex/auth.json.  Downgrade to info so users running
+        # `hermes auth openai-codex` aren't told they're missing something.
+        check_info(
+            "codex CLI not installed "
+            "(optional — only required to import tokens from an existing Codex CLI login)"
+        )
 
     # =========================================================================
     # Check: Directory structure