fix: v0.2.1 — chunked ChatGPT cookies and Claude project path

- Support __Secure-next-auth.session-token.0/.1 split cookies; ChatGPT
  now issues tokens that exceed the 4KB per-cookie limit and must be
  sent as two named chunks or the auth endpoint returns no accessToken.
  Add CHATGPT_SESSION_TOKEN_1 env var; update auth wizard instructions.

- Fix Claude conversations exported to wrong directory when project name
  is present in the listing but absent from the detail endpoint response.
  Explicitly propagate "project" alongside _-prefixed annotation keys.

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

src/config.py

@@ -28,6 +28,7 @@ class ConfigError(Exception):
 @dataclass
 class Config:
     chatgpt_session_token: str | None
+    chatgpt_session_token_1: str | None
     claude_session_key: str | None
     export_dir: Path
     output_structure: str
@@ -55,6 +56,7 @@ def load_config() -> Config:
     load_dotenv(override=False)
 
     chatgpt_token = os.getenv("CHATGPT_SESSION_TOKEN", "").strip() or None
+    chatgpt_token_1 = os.getenv("CHATGPT_SESSION_TOKEN_1", "").strip() or None
     claude_key = os.getenv("CLAUDE_SESSION_KEY", "").strip() or None
     export_dir = Path(os.getenv("EXPORT_DIR", "./exports")).expanduser()
     output_structure = os.getenv("OUTPUT_STRUCTURE", "provider/project/year").strip()
@@ -127,6 +129,7 @@ def load_config() -> Config:
 
     config = Config(
         chatgpt_session_token=chatgpt_token,
+        chatgpt_session_token_1=chatgpt_token_1,
         claude_session_key=claude_key,
         export_dir=export_dir,
         output_structure=output_structure,