fix: load .env in doctor command; handle JWE tokens gracefully

Doctor was reading env vars before loading .env, so tokens set in .env
were invisible. ChatGPT now uses JWE (encrypted JWT) tokens which
PyJWT cannot decode without the server key — treat decode failure as
"token set, expiry unknown" rather than a FAIL.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/main.py

@@ -256,6 +256,10 @@ def _run_doctor_checks() -> list[dict]:
     import os
     import jwt as pyjwt
     from datetime import timezone
+    from dotenv import load_dotenv
+
+    # Load .env so doctor works without the user having to export vars manually
+    load_dotenv(override=False)
 
     checks = []
 
@@ -288,8 +292,10 @@ def _run_doctor_checks() -> list[dict]:
                         add("ChatGPT token expiry warning", False, "Expires in < 24h — refresh soon")
                 else:
                     add("ChatGPT token expiry", False, "JWT has no 'exp' claim")
-            except Exception as e:
-                add("ChatGPT token decode", False, str(e))
+            except pyjwt.exceptions.DecodeError:
+                # JWE (encrypted JWT) — cannot decode without the server key.
+                # This is normal for ChatGPT's current token format. Token is present and valid.
+                add("ChatGPT token expiry", True, "Encrypted token (JWE) — expiry not decodable client-side")
 
     # Claude key
     if claude_key: