Stop the CI from re-fetching crests, cache their URLs instead

Fetching 56 images on every run earned nothing but rate limits, and the
CI artefact is a test build that does not need the badges — the shield
fallback covers it. The resolved image URLs are cached in
tools/crest-sources.json, which is plain text and safe to commit, so a
local run needs one request per club instead of two and can resume after
a rate limit. The artwork itself stays out of the repository.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

tools/fetch-crests.py

@@ -14,11 +14,16 @@ import urllib.parse
 import urllib.request
 
 OUT = sys.argv[1] if len(sys.argv) > 1 else "app/src/main/assets/crests"
+URLS = "tools/crest-sources.json"
 SRC = "app/src/main/java/dev/castarr/tv/data/TeamFilters.kt"
 SUMMARY = "https://de.wikipedia.org/api/rest_v1/page/summary/"
 UA = {"User-Agent": "Castarr build script (private use)"}
 
 os.makedirs(OUT, exist_ok=True)
+# Image URLs are plain text and safe to commit; the artwork itself is not.
+sources = {}
+if os.path.exists(URLS):
+    sources = json.load(open(URLS, encoding="utf-8"))
 kotlin = open(SRC, encoding="utf-8").read()
 entries = re.findall(r'club\((.*?)\)\s*,\s*(?://.*)?$', kotlin, re.M | re.S)
 clubs = []
@@ -35,11 +40,15 @@ for key, full_name in clubs:
         skipped += 1
         continue
     try:
-        url = SUMMARY + urllib.parse.quote(full_name)
-        with urllib.request.urlopen(urllib.request.Request(url, headers=UA), timeout=20) as r:
-            thumb = json.load(r).get("thumbnail", {}).get("source")
+        thumb = sources.get(key)
         if not thumb:
-            raise ValueError("no thumbnail")
+            url = SUMMARY + urllib.parse.quote(full_name)
+            with urllib.request.urlopen(urllib.request.Request(url, headers=UA), timeout=20) as r:
+                thumb = json.load(r).get("thumbnail", {}).get("source")
+            if not thumb:
+                raise ValueError("no thumbnail")
+            sources[key] = thumb.split("?")[0]
+            thumb = sources[key]
         with urllib.request.urlopen(urllib.request.Request(thumb, headers=UA), timeout=20) as r:
             data = r.read()
         with open(target, "wb") as f:
@@ -51,4 +60,8 @@ for key, full_name in clubs:
     # Wikipedia rate-limits bursts; this runs rarely and caches.
     time.sleep(1.2)
 
+with open(URLS, "w", encoding="utf-8") as f:
+    json.dump(dict(sorted(sources.items())), f, indent=2, ensure_ascii=False)
+    f.write("\n")
+
 print(f"crests: {fetched} geladen, {skipped} vorhanden, {failed} fehlgeschlagen")