feat(build): add comprehensive Claude Code executable build system

Add complete build infrastructure for creating single-file Claude Code executables
across all supported platforms using Bun's native compilation features.

- **Cross-platform builds**: Support for Linux (glibc/musl), macOS (Intel/ARM), Windows
- **CPU optimization variants**: Modern (AVX2+) and baseline (pre-2013) CPU support
- **Embedded assets**: All executables include yoga.wasm and ripgrep binaries
- **Optimized builds**: Minification and sourcemaps for production-ready binaries

.gitignore

@@ -12,6 +12,9 @@ dist
 dist-ssr
 *.local
 
+# Tauri binaries (built executables)
+src-tauri/binaries/
+
 # Editor directories and files
 .vscode/*
 !.vscode/extensions.json
@@ -27,4 +30,4 @@ temp_lib/
 .cursor/
 AGENTS.md
 CLAUDE.md
-*_TASK.md
+*_TASK.md