[M5] cargoxx add without version (wildcard)

CHANGELOG.md

@@ -78,11 +78,15 @@ All notable changes to cargoxx will be documented in this file.
   and `[build]` honoring `warnings_as_errors` and `sanitizers`. Source
   paths emitted relative to `build/` (i.e. prefixed with `../`).
   Output is deterministic. `tests/codegen_cmake.cpp` covers 11 cases.
-- `cargoxx add <pkg>@<version> [--components a,b]` edits `Cargoxx.toml`,
+- `cargoxx add <pkg>[@<version>] [--components a,b]` edits `Cargoxx.toml`,
   validates the new dep against the curated linkdb (so unknown packages
   and missing components fail before any disk write), and rejects
-  already-declared deps. Auto-resolution against nixhub.io/lazamar is
-  deferred — for v0.1 the version is required.
+  already-declared deps. Version is now optional; an omitted version
+  is stored as `"*"` and resolves against the linkdb's first matching
+  recipe. Generated `flake.nix` continues to track the `nixos-unstable`
+  branch when the lockfile carries no rev.
+- `util::satisfies` treats `version == "*"` as a match against any
+  range, mirroring the existing `range == "*"` shortcut.
 - `cargoxx remove <pkg>` drops a declared dep from `Cargoxx.toml`,
   errors when the dep is not declared. Other deps are preserved.
 - End-to-end verified on a freshly-scaffolded project. `tests/cmd_add.cpp`