Fix Solr configuration and verify all services

- Add stopwords.txt and synonyms.txt for Solr
- Remove unsupported handlers from solrconfig.xml for Solr 9.x
- Add comprehensive test suite for all backend services
- Verify all 15 containers are running properly
- All services pass health checks successfully

🤖 Generated with [Claude Code](https://claude.ai/code)

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

services/search/solr-config/conf/stopwords.txt

@@ -0,0 +1,35 @@
+# Licensed to the Apache Software Foundation (ASF)
+# Standard English stop words
+a
+an
+and
+are
+as
+at
+be
+but
+by
+for
+if
+in
+into
+is
+it
+no
+not
+of
+on
+or
+such
+that
+the
+their
+then
+there
+these
+they
+this
+to
+was
+will
+with