cub: full AUR package manager + Phase 1-5 native build tools

cub redesign (local/recipes/system/cub/):
- AUR RPC v5 client (serde_json) with search/info
- ~/.cub/ user-local recipe/source/repo storage
- Enhanced PKGBUILD parser: optdepends, .SRCINFO, split packages, 19 linuxism patterns
- Recipe generation: host: prefix on dev-deps, shallow_clone, cargopath, installs, optional-packages
- Dependency resolver: scans build errors for missing commands/headers/libs/pkgconfig, maps to packages
- Dependency installation: checks installed packages, fetches AUR deps, interactive prompt
- ~110 Arc→Redox dependency mappings
- ratatui TUI: search, info, install, build, query views
- 14 Arch-style CLI switches (-S/-Si/-Syu/-G/-R/-Q/-Qi/-Ql)
- 65 tests, 0 failures, clean build

Phase 1-5 native build tools (local/recipes/dev/):
- P1 Substrate: tar, m4, diffutils (gnulib bypass), mkfifo kernel patch (1085 lines)
- P2 Build Systems: bison, flex, meson (standalone wrapper), ninja-build, libtool
- P3 Native GCC: gcc-native, binutils-native (cross-compiled for redox host)
- P4 Native LLVM: llvm-native (clang + lld from monorepo)
- P5 Native Rust: rust-native (rustc + cargo)
- Groups: build-essential-native, dev-essential expanded

Config:
- redbear-mini: +7 tools (diffutils, tar, bison, flex, meson, ninja, m4)
- redbear-full: +4 native tools (gcc, binutils, llvm, rust)
- All recipes moved to local/ with symlinks for cookbook discovery (Red Bear policy)

Docs:
- BUILD-TOOLS-PORTING-PLAN.md: phased porting roadmap
- CUB-WORKFLOW-ASSESSMENT.md: gap analysis and integration assessment

local/recipes/dev/llvm-native/recipe.toml

@@ -0,0 +1,117 @@
+[source]
+same_as = "../../../../recipes/dev/llvm21"
+
+[build]
+template = "custom"
+dependencies = [
+    "llvm21",
+    "llvm21.runtime",
+    "llvm21.dev",
+    "clang21",
+    "lld21",
+    "zstd",
+]
+script = """
+DYNAMIC_INIT
+ARCH="$(echo "${TARGET}" | cut -d - -f1)"
+
+generate_cookbook_cmake_file "$COOKBOOK_HOST_TARGET" "" "$COOKBOOK_TOOLCHAIN" native.cmake
+
+case "${ARCH}" in
+    x86 | x86_64) LLVM_TARGETS_TO_BUILD="X86";;
+    aarch64) LLVM_TARGETS_TO_BUILD="AArch64";;
+    riscv64gc) LLVM_TARGETS_TO_BUILD="RISCV";;
+esac
+
+COOKBOOK_CMAKE_FLAGS+=(
+    -DLLVM_ENABLE_PROJECTS="clang;lld"
+    -DLLVM_BUILD_LLVM_DYLIB=On
+    -DLLVM_LINK_LLVM_DYLIB=On
+    -DLLVM_INCLUDE_UTILS=On
+    -DLLVM_INSTALL_UTILS=On
+    -DLLVM_TARGETS_TO_BUILD="$LLVM_TARGETS_TO_BUILD"
+    -DLLVM_ENABLE_ZLIB=Off
+    -DLLVM_USE_STATIC_ZSTD=On
+    -DLLVM_ENABLE_LIBXML2=Off
+    -DCLANG_LINK_CLANG_DYLIB=ON
+    -DLIBCLANG_BUILD_STATIC=1
+    -DCROSS_TOOLCHAIN_FLAGS_NATIVE="-DCMAKE_TOOLCHAIN_FILE=$(realpath native.cmake)"
+    -DCMAKE_CXX_FLAGS="--std=gnu++11"
+    -DBUILD_SHARED_LIBS=False
+    -DLLVM_BUILD_EXAMPLES=Off
+    -DLLVM_BUILD_TESTS=Off
+    -DLLVM_DEFAULT_TARGET_TRIPLE="${TARGET}"
+    -DLLVM_ENABLE_LTO=Off
+    -DLLVM_ENABLE_RTTI=On
+    -DLLVM_ENABLE_THREADS=On
+    -DLLVM_INCLUDE_EXAMPLES=Off
+    -DLLVM_INCLUDE_TESTS=Off
+    -DLLVM_OPTIMIZED_TABLEGEN=On
+    -DLLVM_TARGET_ARCH=$ARCH
+    -DLLVM_TOOLS_INSTALL_DIR=bin
+    -DLLVM_UTILS_INSTALL_DIR=bin
+    -DUNIX=1
+    -DLLVM_TABLEGEN_EXE=${COOKBOOK_HOST_SYSROOT}/bin/llvm-tblgen
+    -DCLANG_TABLEGEN_EXE=${COOKBOOK_HOST_SYSROOT}/bin/clang-tblgen
+)
+
+COOKBOOK_SOURCE="$COOKBOOK_SOURCE/llvm"
+cookbook_cmake
+
+# Create unprefixed symlinks for native use
+for tool in clang clang++ clang-cpp clang-cl clang-check clang-format clang-tidy \
+    lld ld.lld ld64.lld wasm-ld \
+    llvm-ar llvm-ranlib llvm-nm llvm-objdump llvm-objcopy llvm-strip \
+    llvm-readelf llvm-size llvm-strings llvm-symbolizer llvm-addr2line \
+    llvm-config llvm-link llvm-profdata llvm-cov \
+    llvm-as llvm-dis llc opt; do
+    if [ -f "${COOKBOOK_STAGE}/usr/bin/${tool}" ]; then
+        : # already has unprefixed name
+    elif [ -f "${COOKBOOK_STAGE}/usr/bin/${GNU_TARGET}-${tool}" ]; then
+        ln -sf "${GNU_TARGET}-${tool}" "${COOKBOOK_STAGE}/usr/bin/${tool}"
+    fi
+done
+
+# Provide cc/c++ symlinks
+if [ -f "${COOKBOOK_STAGE}/usr/bin/clang" ]; then
+    ln -sf clang "${COOKBOOK_STAGE}/usr/bin/cc"
+    ln -sf clang++ "${COOKBOOK_STAGE}/usr/bin/c++"
+elif [ -f "${COOKBOOK_STAGE}/usr/bin/${GNU_TARGET}-clang" ]; then
+    ln -sf "${GNU_TARGET}-clang" "${COOKBOOK_STAGE}/usr/bin/cc"
+    ln -sf "${GNU_TARGET}-clang++" "${COOKBOOK_STAGE}/usr/bin/c++"
+fi
+
+# Remove libtool archives
+rm -f "${COOKBOOK_STAGE}"/usr/lib/*.la
+"""
+
+[package]
+description = "Native LLVM/Clang/LLD 21 toolchain for Red Bear OS"
+dependencies = ["llvm21.runtime"]
+
+[[optional-packages]]
+name = "dev"
+dependencies = [".runtime"]
+files = [
+    "usr/include/llvm*/**",
+    "usr/include/clang*/**",
+    "usr/include/lld*/**",
+    "usr/lib/libLLVM*.a",
+    "usr/lib/libclang*.a",
+    "usr/lib/liblld*.a",
+    "usr/lib/cmake/llvm/**",
+    "usr/lib/cmake/clang/**",
+    "usr/lib/cmake/lld/**",
+]
+
+[[optional-packages]]
+name = "runtime"
+files = [
+    "usr/bin/clang*",
+    "usr/bin/lld*",
+    "usr/bin/llvm-*",
+    "usr/bin/llc",
+    "usr/bin/opt",
+    "usr/lib/libLLVM*.so*",
+    "usr/lib/libclang*.so*",
+]