proxy: fix double-prefix when outer proxy mounts a tool at the same name

The 0.1.24 nesting blindly appended the bundled sub-app name to the incoming
X-Forwarded-Prefix, which double-counted it when the outer proxy mounts the app
under the SAME name and proxies to our /<app>/ path (topology B): outer sends
"/township" -> container emitted "/township/township", so every township
fetch() 404'd ("Not found" -> JSON parse error in the UI).

Per-app maps now only append our name when the incoming prefix doesn't already
end in it, so both topologies work: outer-wraps-everything ("/ai" -> "/ai/town
ship") and outer-mounts-same-name ("/township" -> "/township"). Direct (no outer
proxy) still yields "/township".
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01RdMufYvtTbtGDWsiZVoXce

codai/__init__.py

@@ -16,7 +16,7 @@
 
 # Canonical product version for CoderAI — single source of truth. Both the API
 # metadata and the admin web UI read from here.
-__version__ = "0.1.24"
+__version__ = "0.1.25"
 
 # Configure the CUDA caching allocator BEFORE torch is imported anywhere.
 # expandable_segments lets the allocator return freed pages to the driver even

packaging/linux/nginx.conf

@@ -58,13 +58,35 @@ http {
         default $host;
         "~."    $http_x_forwarded_host;
     }
-    # Incoming sub-path prefix from the outer proxy (trailing slash stripped),
-    # so we can NEST our own mount prefixes under it (e.g. outer "/ai" + our
-    # "/township" -> "/ai/township"). Empty when there is no outer prefix.
+    # Incoming sub-path prefix from the outer proxy (trailing slash stripped).
+    # Empty when there is no outer prefix.
     map $http_x_forwarded_prefix $fwd_prefix {
         "~^(?<p>.*?)/?$" $p;
     }
 
+    # Per-app public prefix. Two valid outer-proxy topologies must both work:
+    #   (A) outer wraps the WHOLE container under one prefix and proxies to our
+    #       root: outer sends e.g. "/ai" -> the app's public prefix is
+    #       "/ai/<app>", so we APPEND.
+    #   (B) outer mounts the app at the SAME name and proxies to our "/<app>/"
+    #       path: outer sends e.g. "/township" (or "/ai/township") that ALREADY
+    #       ends in our app name -> use it AS-IS, never append (appending would
+    #       emit "/township/township" and every fetch() would 404).
+    # Rule: if the incoming prefix already ends in "/<app>", pass it through;
+    # otherwise append. Empty incoming -> just "/<app>" (direct, no outer proxy).
+    map $fwd_prefix $xfp_editor {
+        "~/editor$"   $fwd_prefix;
+        default       $fwd_prefix/editor;
+    }
+    map $fwd_prefix $xfp_videogen {
+        "~/videogen$" $fwd_prefix;
+        default       $fwd_prefix/videogen;
+    }
+    map $fwd_prefix $xfp_township {
+        "~/township$" $fwd_prefix;
+        default       $fwd_prefix/township;
+    }
+
     # Shared proxy headers. CoderAI builds public URLs from these
     # (codai/api/urlutils.py); the tools honour X-Forwarded-Prefix for sub-paths.
     proxy_http_version 1.1;
@@ -73,9 +95,9 @@ http {
     proxy_set_header X-Forwarded-For   $proxy_add_x_forwarded_for;
     proxy_set_header X-Forwarded-Proto $fwd_proto;
     proxy_set_header X-Forwarded-Host  $fwd_host;
-    # Pass the outer prefix through unchanged at the root; sub-apps override this
-    # with their own nested value below.
-    proxy_set_header X-Forwarded-Prefix $http_x_forwarded_prefix;
+    # Pass the outer prefix through unchanged at the root (trailing slash
+    # stripped); sub-apps override this with their own value below.
+    proxy_set_header X-Forwarded-Prefix $fwd_prefix;
 
     upstream coderai   { server 127.0.0.1:18776; }
     upstream editor    { server 127.0.0.1:8420;  }
@@ -90,7 +112,7 @@ http {
         # --- Video editor: https://host:8776/editor/ -------------------------
         location /editor/ {
             proxy_pass http://editor/;            # trailing slash strips the prefix
-            proxy_set_header X-Forwarded-Prefix "${fwd_prefix}/editor";  # nest under outer prefix
+            proxy_set_header X-Forwarded-Prefix $xfp_editor;    # smart nest (see map above)
             proxy_request_buffering off;          # stream large uploads through
             proxy_buffering off;                  # SSE progress
         }
@@ -98,7 +120,7 @@ http {
         # --- Videogen studio: https://host:8776/videogen/ -------------------
         location /videogen/ {
             proxy_pass http://videogen/;
-            proxy_set_header X-Forwarded-Prefix "${fwd_prefix}/videogen";  # nest under outer prefix
+            proxy_set_header X-Forwarded-Prefix $xfp_videogen;  # smart nest (see map above)
             proxy_request_buffering off;
             proxy_buffering off;
         }
@@ -106,7 +128,7 @@ http {
         # --- Township fighters: https://host:8776/township/ ----------------
         location /township/ {
             proxy_pass http://township/;
-            proxy_set_header X-Forwarded-Prefix "${fwd_prefix}/township";  # nest under outer prefix
+            proxy_set_header X-Forwarded-Prefix $xfp_township;  # smart nest (see map above)
             proxy_request_buffering off;
             proxy_buffering off;
         }