fix(api.js): restore missing closing brace on graphCommunities()

graphCommunities() was never closed, which silently absorbed every
subsequent method (investigate, forensicsCircularOwnership, ...,
caseMemorySimilar) as if it were still inside it, and left an
orphaned extra closing brace at the end of the object literal.

This was a hard parse-time SyntaxError ('Function statements require
a function name' at the first nested function after the missing
brace), which meant window.Api never got defined at all -- every
Api.* call in the app (search, health, live feed, i18n, ...) threw
ReferenceError.

Verified with: node --check frontend/js/api.js

frontend/js/api.js

@@ -79,6 +79,7 @@ const Api = {
   graphCommunities: function(minSize) {
     var m = minSize ? "?min_size=" + minSize : "";
     return Api._request("/graph/communities" + m);
+  },
 
   // Phase 34: forensic detection
 
@@ -119,7 +120,6 @@ const Api = {
     var p = findingTypes ? "?finding_types=" + encodeURIComponent(findingTypes) : "";
     return Api._request("/case-memory/similar" + p);
   },
-  },
 
   /**
    * BUG-7 FIX: was always sending text as a URL query string on a POST,