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/binutils-native/recipe.toml

@@ -0,0 +1,53 @@
+# Native GNU Binutils 2.43.1 for Red Bear OS
+# Produces binutils that RUN on x86_64-unknown-redox and TARGET x86_64-unknown-redox.
+# Built via cross-compilation from host using the existing cross-compiler in prefix/.
+
+[source]
+same_as = "../../../../recipes/dev/binutils-gdb"
+
+[build]
+template = "custom"
+dependencies = [
+    "gcc13",
+    "gnu-binutils",
+    "libgmp",
+    "libmpfr",
+]
+script = """
+DYNAMIC_INIT
+
+# Use the cross-compiler to produce native redox binaries
+export CC="${COOKBOOK_TARGET}-gcc"
+export CXX="${COOKBOOK_TARGET}-g++"
+export AR="${COOKBOOK_TARGET}-ar"
+export RANLIB="${COOKBOOK_TARGET}-ranlib"
+
+# Configure for native compilation
+COOKBOOK_CONFIGURE_FLAGS+=(
+    --host="${GNU_TARGET}"
+    --target="${GNU_TARGET}"
+    --prefix=/usr
+    --with-sysroot="${COOKBOOK_SYSROOT}"
+    --enable-default-hash-style=gnu
+    --disable-werror
+    --disable-nls
+    --disable-multilib
+)
+
+"${COOKBOOK_CONFIGURE}" "${COOKBOOK_CONFIGURE_FLAGS[@]}"
+"${COOKBOOK_MAKE}" -j "${COOKBOOK_MAKE_JOBS}"
+"${COOKBOOK_MAKE}" install DESTDIR="${COOKBOOK_STAGE}"
+
+# Native binutils don't need the target prefix - provide unprefixed links
+for tool in ar as ld nm objcopy objdump ranlib readelf size strings strip; do
+    if [ -f "${COOKBOOK_STAGE}/usr/bin/${GNU_TARGET}-${tool}" ]; then
+        ln -sf "${GNU_TARGET}-${tool}" "${COOKBOOK_STAGE}/usr/bin/${tool}"
+    fi
+done
+
+# Remove libtool archives
+rm -f "${COOKBOOK_STAGE}"/usr/lib/*.la
+"""
+
+[package]
+description = "Native GNU Binutils 2.43.1 for Red Bear OS (runs on redox, targets redox)"