Initial commit: SCIP indexer for Clojure

Features:
- Generate SCIP index from clojure-lsp dump
- Namespace definitions and usages
- Var definitions and usages
- Namespace alias definitions and usage references
- External symbol documentation for hover

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

.gitignore

@@ -0,0 +1,5 @@
+.cpcache/
+classes/
+*.jar
+.lsp/
+.clj-kondo/