fix(translate): forward upstream redirects instead of following them

urlopen() follows redirects silently. Kiwix answers a book root such as
/content/<book> with a 302 to the ZIM's main page, so the proxy served
that page's HTML at the original, shallower URL. Every relative link and
stylesheet then resolved one directory too high: the page lost its
styling and every article link 404'd (e.g. atenolol/ -> /content/atenolol/).
Kiwix's /random is a 302 too and broke the same way.

Use an opener that returns 3xx to the browser like any other non-200
response, and keep an absolute Location on this origin rather than the
upstream container name.

Bumps the catalog image to 0.1.1.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

admin/database/seeders/service_seeder.ts

@@ -550,7 +550,7 @@ export default class ServiceSeeder extends BaseSeeder {
       description:
         'Read the Information Library in another language. Machine translation that works offline, on CPU',
       icon: 'IconWorld',
-      container_image: 'ghcr.io/crosstalk-solutions/project-nomad-translate:0.1.0',
+      container_image: 'ghcr.io/crosstalk-solutions/project-nomad-translate:0.1.1',
       source_repo: 'https://github.com/browsermt/bergamot-translator',
       container_command: null,
       container_config: JSON.stringify({

install/nomad-translate/proxy.py

@@ -40,6 +40,24 @@ MAX_TRANSLATE_BYTES = int(os.environ.get("MAX_TRANSLATE_BYTES", str(4 * 1024 * 1
 
 COOKIE = "nomadlang"
 
+
+class _NoRedirect(urllib.request.HTTPRedirectHandler):
+    """Hand upstream redirects back to the browser instead of following them.
+
+    Kiwix answers a book root such as /content/<book> with a 302 to the ZIM's
+    main page. Following it here would serve that page's HTML at the ORIGINAL
+    URL, so every relative link and stylesheet in it resolves one directory
+    too high: styling is lost and every article link 404s.
+    """
+
+    def redirect_request(self, *args, **kwargs):
+        return None
+
+
+# urlopen() follows redirects by default; this opener raises them as HTTPError
+# so they are forwarded below like any other non-200 response.
+_opener = urllib.request.build_opener(_NoRedirect)
+
 # Display names for the languages Bergamot's tiny model set covers. A language
 # only appears in the control if its model is actually on disk.
 LANG_NAMES = {
@@ -226,12 +244,18 @@ class Handler(BaseHTTPRequestHandler):
         # HTML can be rewritten without decompressing first.
 
         try:
-            response = urllib.request.urlopen(request, timeout=120)
+            response = _opener.open(request, timeout=120)
             status, headers, data = response.status, response.headers, response.read()
         except urllib.error.HTTPError as exc:
             # Forwarded as-is, which is how Kiwix's own 404 and 400 pages keep
             # coming back byte for byte.
             status, headers, data = exc.code, exc.headers, exc.read()
+            # An absolute Location would point the browser at the upstream
+            # container name, which it cannot reach. Keep it on this origin.
+            location = headers.get("Location", "")
+            if location.startswith(UPSTREAM):
+                del headers["Location"]
+                headers["Location"] = location[len(UPSTREAM):] or "/"
         except Exception as exc:
             message = f"Translation proxy could not reach the library: {exc}".encode()
             self.send_response(502)