chore: rebrand Clojure/Nim → Bara Lang across codebase

- Bulk replace Clojure/Nim → Bara Lang in src/, lib/, examples/, benchmarks/,
  experiments/, books/, LICENSE, cljnim.nimble, PLAN.md, AI_AGENT.md
- Rename book chapters: 05-clojure-nim.md → 05-bara-lang.md (en + bg)
- Update all chapter index links and anchors
- Replace project-specific 'Clojure' references with 'Bara Lang' in
  experiments/, src/ai_assist.nim, src/tui_screens.nim, src/emitter.nim,
  src/reader.nim, src/types.nim, lib/cljnim_runtime*.nim
- Keep legitimate JVM Clojure/ClojureScript/Clojure CLR references intact

experiments/wasm-target/wasm_wrappers.nim

@@ -1,4 +1,4 @@
-# WASM-friendly wrappers around Clojure-generated code
+# WASM-friendly wrappers around Bara Lang-generated code
 # Uses Emscripten FFI: cint → JS number, cstring → JS string
 
 import cljnim_runtime