Fix auth to use form data instead of JSON

L2 server now uses HTML form endpoints for login/register.
Updated client to:
- Send form data instead of JSON
- Extract token from cookie response
- Decode JWT to get username and expiry
- Handle HTML success/error responses

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

artdag.py

@@ -102,17 +102,48 @@ def cli(ctx, server, l2):
 def login(username, password):
     """Login to get access token."""
     try:
+        # Server expects form data, not JSON
         resp = requests.post(
             f"{get_l2_server()}/auth/login",
-            json={"username": username, "password": password}
+            data={"username": username, "password": password}
         )
         if resp.status_code == 200:
-            token_data = resp.json()
+            # Check if we got a token back in a cookie
+            if "auth_token" in resp.cookies:
+                token = resp.cookies["auth_token"]
+                # Decode token to get username and expiry
+                import base64
+                try:
+                    # JWT format: header.payload.signature
+                    payload = token.split(".")[1]
+                    # Add padding if needed
+                    payload += "=" * (4 - len(payload) % 4)
+                    decoded = json.loads(base64.urlsafe_b64decode(payload))
+                    token_data = {
+                        "access_token": token,
+                        "username": decoded.get("username", username),
+                        "expires_at": decoded.get("exp", "")
+                    }
                     save_token(token_data)
                     click.echo(f"Logged in as {token_data['username']}")
+                    if token_data.get("expires_at"):
                         click.echo(f"Token expires: {token_data['expires_at']}")
+                except Exception:
+                    # If we can't decode, just save the token
+                    save_token({"access_token": token, "username": username})
+                    click.echo(f"Logged in as {username}")
             else:
-            click.echo(f"Login failed: {resp.json().get('detail', 'Unknown error')}", err=True)
+                # HTML response - check for success/error
+                if "successful" in resp.text.lower():
+                    click.echo(f"Login successful but no token received. Try logging in via web browser.")
+                elif "invalid" in resp.text.lower():
+                    click.echo(f"Login failed: Invalid username or password", err=True)
+                    sys.exit(1)
+                else:
+                    click.echo(f"Login failed: {resp.text}", err=True)
+                    sys.exit(1)
+        else:
+            click.echo(f"Login failed: {resp.text}", err=True)
             sys.exit(1)
     except requests.RequestException as e:
         click.echo(f"Login failed: {e}", err=True)
@@ -126,16 +157,51 @@ def login(username, password):
 def register(username, password, email):
     """Register a new account."""
     try:
+        # Server expects form data, not JSON
+        form_data = {
+            "username": username,
+            "password": password,
+            "password2": password,
+        }
+        if email:
+            form_data["email"] = email
+
         resp = requests.post(
             f"{get_l2_server()}/auth/register",
-            json={"username": username, "password": password, "email": email}
+            data=form_data
         )
         if resp.status_code == 200:
-            token_data = resp.json()
+            # Check if we got a token back in a cookie
+            if "auth_token" in resp.cookies:
+                token = resp.cookies["auth_token"]
+                # Decode token to get username and expiry
+                import base64
+                try:
+                    # JWT format: header.payload.signature
+                    payload = token.split(".")[1]
+                    # Add padding if needed
+                    payload += "=" * (4 - len(payload) % 4)
+                    decoded = json.loads(base64.urlsafe_b64decode(payload))
+                    token_data = {
+                        "access_token": token,
+                        "username": decoded.get("username", username),
+                        "expires_at": decoded.get("exp", "")
+                    }
                     save_token(token_data)
                     click.echo(f"Registered and logged in as {token_data['username']}")
+                except Exception:
+                    # If we can't decode, just save the token
+                    save_token({"access_token": token, "username": username})
+                    click.echo(f"Registered and logged in as {username}")
             else:
-            click.echo(f"Registration failed: {resp.json().get('detail', 'Unknown error')}", err=True)
+                # HTML response - registration successful
+                if "successful" in resp.text.lower():
+                    click.echo(f"Registered as {username}. Please login to get a token.")
+                else:
+                    click.echo(f"Registration failed: {resp.text}", err=True)
+                    sys.exit(1)
+        else:
+            click.echo(f"Registration failed: {resp.text}", err=True)
             sys.exit(1)
     except requests.RequestException as e:
         click.echo(f"Registration failed: {e}", err=True)