feat: Enhance dependency management and project setup

- Added support for registry-based dependencies in the dependencies section.
- Updated the package section to include a project type field.
- Introduced a new CLI command `dcr setup` to load and display registry configurations.
- Implemented a new module for handling registry operations, including loading and resolving packages from registries.
- Enhanced the build process to handle library packaging, including copying headers and libraries to the appropriate target directories.
- Updated the CLI to support building library packages and added tests for library package builds.
- Improved error handling and output messages during dependency resolution and package fetching.

docs/configuration/dependencies-section.md

@@ -1,23 +1,36 @@
 # Dependencies section
 
-DCR currently supports path dependencies.
+DCR supports registry-based dependencies and path dependencies.
 
 ## Example
 
 ```toml
 [dependencies]
+# Registry dependency
+mylib = "0.1.0"
+# Git dependency
+json = { git = "https://github.com/nlohmann/json", tag = "v3.11.2" }
+# Path dependency
 frecli = { path = "./lib/frecli", include = ["."], lib = ["."], libs = ["frecli"] }
 ```
 
-## Supported fields per dependency
+## Supported dependency types
 
+### Registry dependencies
+Defined by name and version string. DCR automatically resolves the package from the configured registry index.
+
+### Git dependencies
+Defined by repository URL and optionally branch, tag, or revision.
+- `git` (string, required): repository URL.
+- `branch`, `tag`, `rev` (string, optional): Git reference.
+
+### Path dependencies
 - `path` (string, required): absolute path or path relative to project root.
 - `include` (string array, optional): include directories inside dependency.
 - `lib` (string array, optional): library directories inside dependency.
 - `libs` (string array, optional): library names for linker.
-- `system` (bool, optional): currently `system = true` is rejected.
 
-## Defaults
+## Defaults for path dependencies
 
 - If `include` is omitted, DCR tries `<dep>/include`.
 - If `lib` is omitted, DCR tries `<dep>/lib`, then `<dep>/lib64`.
@@ -25,6 +38,7 @@ frecli = { path = "./lib/frecli", include = ["."], lib = ["."], libs = ["frecli"
 
 ## Validation
 
-- Dependency value must be a TOML table.
-- `path` is mandatory.
+- Dependency value must be a string (registry) or a TOML table (path).
+- Registry dependencies use the version string to match versions in the registry.
+- `path` is mandatory for path dependencies.
 - `include`/`lib`/`libs` must be arrays of strings if provided.

docs/configuration/package-section.md

@@ -6,15 +6,18 @@
 [package]
 name = "my-app"
 version = "0.1.0"
+type = "app"
 ```
 
 ## Fields
 
 - `name` (string, required): used as output artifact base name.
 - `version` (string, required): used in `dcr.lock` project entry.
+- `type` (string, optional): project type (`app`, `lib`, `none`).
 
 ## Notes
 
 - Empty `name` or `version` makes config invalid.
 - `dcr new` sets `name` from the passed project name.
 - `dcr init` sets `name` from current directory name.
+- If `type = "lib"`, DCR generates `include/` and `lib/` directories in the target path, copying public headers and built libraries.