feat: normalize base_url and strip credentials from logs

New url_util.py (deliberately separate from the vendored files, so a
future upstream re-sync never conflicts with it): normalize_base_url
strips whitespace/trailing slashes and rejects non-http(s) or hostless
URLs; sanitize_url_for_logging masks embedded basic-auth credentials
for Task 7's discovery logging.

Wires normalization into config_flow.validate_input before the client
is built, with a new invalid_base_url form error.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01739Seac5eMAfNwFeiwV5r4

custom_components/openai_compatible/config_flow.py

@@ -103,6 +103,7 @@ from .const import (
     UNSUPPORTED_PRIORITY_SERVICE_TIERS_MODELS,
     UNSUPPORTED_WEB_SEARCH_MODELS,
 )
+from .url_util import InvalidBaseURL, normalize_base_url
 
 _LOGGER = logging.getLogger(__name__)
 
@@ -119,6 +120,7 @@ async def validate_input(hass: HomeAssistant, data: dict[str, Any]) -> None:
 
     Data has the keys from STEP_USER_DATA_SCHEMA with values provided by the user.
     """
+    data[CONF_BASE_URL] = normalize_base_url(data[CONF_BASE_URL])
     client = openai.AsyncOpenAI(
         api_key=data[CONF_API_KEY],
         base_url=data[CONF_BASE_URL],
@@ -145,6 +147,8 @@ class OpenAIConfigFlow(ConfigFlow, domain=DOMAIN):
             self._async_abort_entries_match(user_input)
             try:
                 await validate_input(self.hass, user_input)
+            except InvalidBaseURL:
+                errors["base"] = "invalid_base_url"
             except openai.APIConnectionError:
                 errors["base"] = "cannot_connect"
             except openai.AuthenticationError:

custom_components/openai_compatible/strings.json

@@ -7,6 +7,7 @@
     "error": {
       "cannot_connect": "[%key:common::config_flow::error::cannot_connect%]",
       "invalid_auth": "[%key:common::config_flow::error::invalid_auth%]",
+      "invalid_base_url": "That does not look like a valid http(s) URL.",
       "unknown": "[%key:common::config_flow::error::unknown%]"
     },
     "step": {

custom_components/openai_compatible/url_util.py

@@ -0,0 +1,42 @@
+"""Base-URL normalization and safe logging.
+
+This module is intentionally separate from the vendored upstream files so that
+re-syncing with home-assistant/core never conflicts with it.
+"""
+
+from __future__ import annotations
+
+from urllib.parse import urlparse, urlunparse
+
+ALLOWED_SCHEMES = frozenset({"http", "https"})
+
+
+class InvalidBaseURL(ValueError):
+    """Raised when a base URL is unusable."""
+
+
+def normalize_base_url(url: str) -> str:
+    """Strip whitespace and trailing slashes, and validate the scheme."""
+    cleaned = (url or "").strip()
+    if not cleaned:
+        raise InvalidBaseURL("base URL is empty")
+
+    parsed = urlparse(cleaned)
+    if parsed.scheme not in ALLOWED_SCHEMES:
+        raise InvalidBaseURL(f"unsupported scheme: {parsed.scheme or '(none)'}")
+    if not parsed.netloc:
+        raise InvalidBaseURL("base URL has no host")
+
+    return urlunparse(parsed._replace(path=parsed.path.rstrip("/")))
+
+
+def sanitize_url_for_logging(url: str) -> str:
+    """Return the URL with any embedded credentials replaced by ***."""
+    parsed = urlparse(url)
+    if not parsed.username and not parsed.password:
+        return url
+
+    host = parsed.hostname or ""
+    if parsed.port:
+        host = f"{host}:{parsed.port}"
+    return urlunparse(parsed._replace(netloc=f"***@{host}"))