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

books/clojure-book/en/index.md

@@ -24,10 +24,10 @@
 
 - **Caching** - [1.5](en/01-fundamentals.md#15-memoization), [8.6](en/02-advanced.md#86-preload-and-cache), [8.2](en/04-recipes.md#82-caching-with-ttl)
 - **Case** - [6.1.5](en/01-fundamentals.md#615-case)
-- **Channels** - [16.1](en/01-fundamentals.md#161-channels), [5](en/05-clojure-nim.md#concurrency)
-- **Clojure/Nim** - [5](en/05-clojure-nim.md) — Native compilation, AI integration, JSON REPL
-- **Compilation (native)** - [5](en/05-clojure-nim.md#what-is-clojure-nim)
-- **Cross-compilation** - [5](en/05-clojure-nim.md#cross-compilation-targets) — JS, WASM, shared libraries
+- **Channels** - [16.1](en/01-fundamentals.md#161-channels), [5](en/05-bara-lang.md#concurrency)
+- **Bara Lang** - [5](en/05-bara-lang.md) — Native compilation, AI integration, JSON REPL
+- **Compilation (native)** - [5](en/05-bara-lang.md#what-is-bara-lang)
+- **Cross-compilation** - [5](en/05-bara-lang.md#cross-compilation-targets) — JS, WASM, shared libraries
 - **Characters** - [4.3](en/01-fundamentals.md#43-characters)
 - **Chunked sequences** - [2.2](en/02-advanced.md#22-chunked-sequences)
 - **Circuit breaker** - [3.4](en/04-recipes.md#34-circuit-breaker)