dcr Files

Fixed:

• Path dependencies now work correctly: dcr add stores them as { path = "./..." } tables, is_registry_dep properly distinguishes registry strings from path/git strings, and deps/mod.rs resolves both table-form and legacy string-form path dependencies
• Registry dependency paths no longer hardcoded to project_root/dcr-index; now use package_root_from_registry_info() which resolves relative to the registry cache root (~/.dcr/)
• Registry dependencies are now actually built: build_project_at() is called when include_dir or lib_dir is missing

Added:

• SIGINT/Ctrl+C handler via ctrlc crate — dcr build now checks BUILD_INTERRUPTED flag at key points and aborts cleanly
• utils/build.rs — extracted shared utilities: parse_version_info, normalize_target_os, resolve_compiler, primary_language, resolve_pkg_config_flags and config helpers. Eliminates code duplication between cli/build.rs, cli/run.rs, cli/clean.rs, cli/gen.rs
• utils/fs.rs::with_dir — extracted common directory-scoped execution
• run_command_sync_output in builder/common.rs with global OUTPUT_MUTEX — synchronized compiler output across all backends (unix_cc, gas, nasm, msvc)
• New helper functions in deps/register.rs: get_registry_cache_root, package_root_from_registry_info, registry_include_dir, registry_lib_dir, path_from_string_dep
• Unit tests for register.rs (is_registry_dep, package_root_from_registry_info), deps/mod.rs (path_dep_path, push_default_lib_dirs), utils/build.rs (normalize_target_os, parse_version_info)
• dcr tree command — visual dependency tree viewer (similar to cargo tree)

Removed:

• Removed unused dependencies indicatif and console from Cargo.toml