fix(resolver): seed root package into pool as fixed entry

Composer's RootPackageRepository puts a clone of the root package into
the pool as a fixed entry — its `require` / `require-dev` cleared, but
its name, version, provides, and replaces preserved. That way a
transitive `require` pointing back at the root resolves through the
pool the same way any other reference would, and legal circular
dependencies (root requires A, A requires root) work.

Mozart had no such seed: the rule generator only knew about the root
through the explicit root-require / root-provide / root-replace tables,
so a transitive consumer requiring the root by name failed with no
provider.

Plumb root_version through ResolveRequest (RawPackageData gains a
matching `Option<String>` field), build a fixed PoolPackageInput for
the root with provides/replaces lifted from request.root_provide /
root_replace, and skip the root by name when collecting the resolver's
output so it doesn't leak into the lock file. Falls back to
`1.0.0+no-version-set` (Composer's RootPackage::DEFAULT_PRETTY_VERSION)
when the root composer.json omits `version`.

Unblocks circular_dependency2, conflict_against_replaced_package_problem,
and provider_conflicts installer fixtures.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/crates/mozart/src/commands/update.rs b/crates/mozart/src/commands/update.rs
index 0c25a9e..db9d616 100644
--- a/crates/mozart/src/commands/update.rs
+++ b/crates/mozart/src/commands/update.rs
@@ -883,6 +883,7 @@ pub async fn run(
 
     let request = ResolveRequest {
         root_name: composer_json.name.clone(),
+        root_version: composer_json.version.clone(),
         require,
         require_dev,
         include_dev: dev_mode,
@@ -1993,6 +1994,7 @@ mod tests {
 
         let request = ResolveRequest {
             root_name: String::new(),
+            root_version: None,
             require: vec![("monolog/monolog".to_string(), "^3.0".to_string())],
             require_dev: vec![],
             include_dev: false,