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/rust-native/config.toml

@@ -0,0 +1,29 @@
+[llvm]
+download-ci-llvm = false
+static-libstdcpp = false
+link-shared = true
+
+[build]
+host = ["COOKBOOK_TARGET"]
+target = ["COOKBOOK_TARGET"]
+submodules = false
+docs = false
+tools = ["cargo", "clippy", "rustdoc", "rustfmt", "src"]
+extended = true
+verbose = 1
+
+[install]
+prefix = "install"
+sysconfdir = "etc"
+
+[rust]
+backtrace = false
+codegen-tests = false
+
+[target.COOKBOOK_TARGET]
+cc = "COOKBOOK_GNU_TARGET-gcc"
+cxx = "COOKBOOK_GNU_TARGET-g++"
+ar = "COOKBOOK_GNU_TARGET-ar"
+linker = "COOKBOOK_GNU_TARGET-gcc"
+crt-static = false
+llvm-config = "COOKBOOK_SYSROOT/bin/llvm-config"

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

@@ -0,0 +1,39 @@
+[source]
+same_as = "../../../../recipes/dev/rust"
+
+[build]
+template = "custom"
+dependencies = [
+    "zlib",
+    "curl",
+    "openssl3",
+    "llvm-native",
+    "llvm-native.runtime",
+]
+script = """
+DYNAMIC_INIT
+ARCH="${TARGET%%-*}"
+export CARGO_TARGET_${ARCH^^}_UNKNOWN_REDOX_RUSTFLAGS="${RUSTFLAGS}"
+cat "${COOKBOOK_ROOT}/bin/${TARGET}-llvm-config" > "${COOKBOOK_SYSROOT}/bin/llvm-config"
+export LD_LIBRARY_PATH="${COOKBOOK_HOST_SYSROOT}/lib:${LD_LIBRARY_PATH}"
+
+cat ${COOKBOOK_RECIPE}/config.toml > config.toml
+sed -i "s|COOKBOOK_SYSROOT|${COOKBOOK_SYSROOT}|g" config.toml
+sed -i "s|COOKBOOK_TOOLCHAIN|${COOKBOOK_HOST_SYSROOT}|g" config.toml
+sed -i "s|COOKBOOK_TARGET|${TARGET}|g" config.toml
+sed -i "s|COOKBOOK_GNU_TARGET|${GNU_TARGET}|g" config.toml
+
+unset AR AS CC CXX LD LDFLAGS NM OBJCOPY OBJDUMP RANLIB READELF RUSTFLAGS CARGO_ENCODED_RUSTFLAGS STRIP
+
+python3 "${COOKBOOK_SOURCE}/x.py" install \
+    --config config.toml \
+    --jobs ${COOKBOOK_MAKE_JOBS}
+
+mkdir -p "${COOKBOOK_STAGE}"/usr
+rsync -av --delete "${COOKBOOK_BUILD}"/install/* "${COOKBOOK_STAGE}"/usr/
+rm -rf "${COOKBOOK_STAGE}"/usr/lib/rustlib/*.log
+"""
+
+[package]
+description = "Native Rust toolchain for Red Bear OS (rustc + cargo running on redox)"
+dependencies = ["llvm-native.runtime"]