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

lib/cljnim_runtime.nim

@@ -481,7 +481,7 @@ proc cljNumEq*(args: seq[CljVal]): CljVal =
   cljBool(true)
 
 proc cljEqual*(a, b: CljVal): bool =
-  ## Clojure = equality: structural equality for all types, numeric equality for numbers
+  ## Bara Lang = equality: structural equality for all types, numeric equality for numbers
   if a.isNil and b.isNil: return true
   if a.isNil or b.isNil: return false
   if a.kind != b.kind: