fix: add MEALIE_INTERNAL_URL env var for Docker-to-Docker API calls

When deployed behind Cloudflare Tunnel, requests from the container to
the external Mealie URL fail with 530 (hairpin). MEALIE_INTERNAL_URL
lets the container use the Docker-internal address (e.g. http://mealie:9000)
for API calls while keeping the external URL for browser links.

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

app/mealie.py

@@ -8,8 +8,9 @@ import requests
 class MealieClient:
     """Thin wrapper around the Mealie REST API."""
 
-    def __init__(self, base_url: str, api_key: str):
+    def __init__(self, base_url: str, api_key: str, api_url: str = ""):
         self.base_url = base_url.rstrip("/")
+        self.api_url = api_url.rstrip("/") if api_url else self.base_url
         self.session = requests.Session()
         self.session.headers.update({
             "Authorization": f"Bearer {api_key}",
@@ -22,7 +23,7 @@ class MealieClient:
 
     def test_connection(self) -> dict:
         """Return Mealie app info or raise on failure."""
-        r = self.session.get(f"{self.base_url}/api/app/about", timeout=10)
+        r = self.session.get(f"{self.api_url}/api/app/about", timeout=10)
         r.raise_for_status()
         return r.json()
 
@@ -34,7 +35,7 @@ class MealieClient:
         """
         # Step 1: create stub
         r = self.session.post(
-            f"{self.base_url}/api/recipes",
+            f"{self.api_url}/api/recipes",
             json={"name": recipe["title"]},
             timeout=15,
         )
@@ -44,7 +45,7 @@ class MealieClient:
         # Step 2: build full payload and PATCH
         payload = self._build_payload(recipe)
         r = self.session.patch(
-            f"{self.base_url}/api/recipes/{slug}",
+            f"{self.api_url}/api/recipes/{slug}",
             json=payload,
             timeout=15,
         )
@@ -107,7 +108,7 @@ class MealieClient:
             "image": (f"recipe.{ext}", io.BytesIO(img_resp.content), content_type),
         }
         r = self.session.put(
-            f"{self.base_url}/api/recipes/{slug}/image",
+            f"{self.api_url}/api/recipes/{slug}/image",
             files=files,
             timeout=30,
         )