refactor(vcs): mirror Composer interfaces; rename get_local_changes

- Rename `local_changes` → `get_local_changes` to match Composer's
  `getLocalChanges`
- Add `is_change_report`, `is_vcs_capable_downloader`,
  `is_dvcs_downloader` trait methods to replace PHP `instanceof` checks
- Add `VersionParser` stub to keep `VersionGuesser::new` signature
  compatible with Composer's constructor
- Add `ArrayDumper` in status.rs mirroring
  `Composer\Package\Dumper\ArrayDumper`; expand `build_package_config`
  to include all fields that `VersionGuesser` inspects

6 files changed, 76 insertions, 9 deletions

diff --git a/crates/mozart-vcs/src/downloader/git.rs b/crates/mozart-vcs/src/downloader/git.rs
index 0c78f89..814d67e 100644
--- a/crates/mozart-vcs/src/downloader/git.rs
+++ b/crates/mozart-vcs/src/downloader/git.rs
@@ -96,7 +96,7 @@ impl VcsDownloader for GitDownloader {
         Ok(())
     }
 
-    fn local_changes(&self, target: &Path) -> Result<Option<String>> {
+    fn get_local_changes(&self, target: &Path) -> Result<Option<String>> {
         if !target.join(".git").exists() {
             return Ok(None);
         }
@@ -223,6 +223,18 @@ impl VcsDownloader for GitDownloader {
         )?;
         Ok(output.stdout)
     }
+
+    fn is_change_report(&self) -> bool {
+        true
+    }
+
+    fn is_vcs_capable_downloader(&self) -> bool {
+        true
+    }
+
+    fn is_dvcs_downloader(&self) -> bool {
+        true
+    }
 }
 
 fn collect_show_ref(process: &ProcessExecutor, target: &Path) -> Result<Option<String>> {
diff --git a/crates/mozart-vcs/src/downloader/hg.rs b/crates/mozart-vcs/src/downloader/hg.rs
index 926cfa8..3230404 100644
--- a/crates/mozart-vcs/src/downloader/hg.rs
+++ b/crates/mozart-vcs/src/downloader/hg.rs
@@ -45,7 +45,7 @@ impl VcsDownloader for HgDownloader {
         Ok(())
     }
 
-    fn local_changes(&self, target: &Path) -> Result<Option<String>> {
+    fn get_local_changes(&self, target: &Path) -> Result<Option<String>> {
         if !target.join(".hg").is_dir() {
             return Ok(None);
         }
@@ -72,4 +72,16 @@ impl VcsDownloader for HgDownloader {
         )?;
         Ok(output.stdout)
     }
+
+    fn is_change_report(&self) -> bool {
+        true
+    }
+
+    fn is_vcs_capable_downloader(&self) -> bool {
+        true
+    }
+
+    fn is_dvcs_downloader(&self) -> bool {
+        false
+    }
 }
diff --git a/crates/mozart-vcs/src/downloader/mod.rs b/crates/mozart-vcs/src/downloader/mod.rs
index 8948921..352f330 100644
--- a/crates/mozart-vcs/src/downloader/mod.rs
+++ b/crates/mozart-vcs/src/downloader/mod.rs
@@ -25,7 +25,7 @@ pub trait VcsDownloader {
     /// Detect local changes in the working copy.
     /// Returns `None` if clean, `Some(diff)` if modified.
     /// Mirrors `Composer\Downloader\ChangeReportInterface::getLocalChanges`.
-    fn local_changes(&self, target: &Path) -> Result<Option<String>>;
+    fn get_local_changes(&self, target: &Path) -> Result<Option<String>>;
 
     /// Detect commits present locally but not on the tracking remote.
     /// Returns `None` if there are no unpushed commits or the concept does
@@ -44,4 +44,13 @@ pub trait VcsDownloader {
 
     /// Get commit log between two references.
     fn commit_logs(&self, from: &str, to: &str, target: &Path) -> Result<String>;
+
+    /// instanceof ChangeReportInterface
+    fn is_change_report(&self) -> bool;
+
+    /// instanceof VcsCapableDownloaderInterface
+    fn is_vcs_capable_downloader(&self) -> bool;
+
+    /// instanceof DvcsDownloaderInterface
+    fn is_dvcs_downloader(&self) -> bool;
 }
diff --git a/crates/mozart-vcs/src/downloader/svn.rs b/crates/mozart-vcs/src/downloader/svn.rs
index 533e15a..87b59da 100644
--- a/crates/mozart-vcs/src/downloader/svn.rs
+++ b/crates/mozart-vcs/src/downloader/svn.rs
@@ -51,7 +51,7 @@ impl VcsDownloader for SvnDownloader {
         Ok(())
     }
 
-    fn local_changes(&self, target: &Path) -> Result<Option<String>> {
+    fn get_local_changes(&self, target: &Path) -> Result<Option<String>> {
         if !target.join(".svn").is_dir() {
             return Ok(None);
         }
@@ -72,4 +72,16 @@ impl VcsDownloader for SvnDownloader {
             .execute(&["log", "-r", &range], Some(target))?;
         Ok(output.stdout)
     }
+
+    fn is_change_report(&self) -> bool {
+        true
+    }
+
+    fn is_vcs_capable_downloader(&self) -> bool {
+        true
+    }
+
+    fn is_dvcs_downloader(&self) -> bool {
+        false
+    }
 }
diff --git a/crates/mozart-vcs/src/version_guesser.rs b/crates/mozart-vcs/src/version_guesser.rs
index e70eb4e..038e332 100644
--- a/crates/mozart-vcs/src/version_guesser.rs
+++ b/crates/mozart-vcs/src/version_guesser.rs
@@ -20,6 +20,25 @@ use crate::process::ProcessExecutor;
 
 const DEFAULT_BRANCH_ALIAS: &str = "9999999-dev";
 
+/// Mirrors `Composer\Package\Version\VersionParser` (itself a thin wrapper
+/// around `Composer\Semver\VersionParser`). In Rust, semver parsing is
+/// handled by `mozart_semver` directly, so this type carries no state;
+/// it exists to keep `VersionGuesser::new` signature compatible with the
+/// PHP constructor.
+pub struct VersionParser;
+
+impl Default for VersionParser {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+impl VersionParser {
+    pub fn new() -> Self {
+        Self
+    }
+}
+
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct GuessedVersion {
     pub version: String,
@@ -35,12 +54,15 @@ pub struct VersionGuesser {
 
 impl Default for VersionGuesser {
     fn default() -> Self {
-        Self::new()
+        Self::new(VersionParser::new())
     }
 }
 
 impl VersionGuesser {
-    pub fn new() -> Self {
+    /// Mirrors `Composer\Package\Version\VersionGuesser::__construct`.
+    /// `_version_parser` is accepted for API parity but unused — Rust relies
+    /// on `mozart_semver` directly.
+    pub fn new(_version_parser: VersionParser) -> Self {
         Self {
             process: ProcessExecutor::new(),
         }
diff --git a/crates/mozart-vcs/tests/git_driver_test.rs b/crates/mozart-vcs/tests/git_driver_test.rs
index 2654665..dd72ad6 100644
--- a/crates/mozart-vcs/tests/git_driver_test.rs
+++ b/crates/mozart-vcs/tests/git_driver_test.rs
@@ -165,13 +165,13 @@ fn test_git_downloader() {
     assert!(target.join("composer.json").exists());
 
     // Check no local changes
-    let changes = downloader.local_changes(&target).unwrap();
+    let changes = downloader.get_local_changes(&target).unwrap();
     assert!(changes.is_none(), "Expected no changes, got: {:?}", changes);
 
     // Untracked files alone must NOT count as local changes (matches
     // Composer's `git status --porcelain --untracked-files=no`).
     std::fs::write(target.join("untracked.txt"), "untracked").unwrap();
-    let changes = downloader.local_changes(&target).unwrap();
+    let changes = downloader.get_local_changes(&target).unwrap();
     assert!(
         changes.is_none(),
         "Untracked files should be ignored, got: {:?}",
@@ -180,7 +180,7 @@ fn test_git_downloader() {
 
     // Modifying a tracked file is a local change.
     std::fs::write(target.join("composer.json"), "{\"name\":\"changed\"}\n").unwrap();
-    let changes = downloader.local_changes(&target).unwrap();
+    let changes = downloader.get_local_changes(&target).unwrap();
     assert!(changes.is_some());
     assert!(changes.unwrap().contains("composer.json"));