fix(browse): mirror Composer's HomeCommand semantics

Replace the hand-rolled composer.json -> composer.lock -> Packagist
fallback with a BrowseRepos composite that dispatches via a uniform
find_packages(name) over the root package, the local installed
repository, and the Packagist remote -- matching HomeCommand's
initializeRepos() + findPackages() loop.

- Extend InstalledPackageEntry with homepage/support so the local repo
  carries the same fields HomeCommand reads off
  CompletePackageInterface; propagate them through
  locked_to_installed_entry.
- Collapse three extract_url_from_* helpers into a single
  handle_package mirror.
- Relax is_valid_url to a filter_var(FILTER_VALIDATE_URL) analog (drop
  the http/https scheme allowlist).
- Route warnings and "No package specified" notices to stderr; match
  HomeCommand's exact wording.
- Merge the macOS/Linux open_browser branches; add the literal "web"
  window-title argument on Windows.

1 files changed, 32 insertions, 0 deletions

diff --git a/crates/mozart-registry/src/installed.rs b/crates/mozart-registry/src/installed.rs
index 6e8e0ac..da02c6a 100644
--- a/crates/mozart-registry/src/installed.rs
+++ b/crates/mozart-registry/src/installed.rs
@@ -48,6 +48,12 @@ pub struct InstalledPackageEntry {
     #[serde(default, skip_serializing_if = "Vec::is_empty")]
     pub aliases: Vec<String>,
 
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub homepage: Option<String>,
+
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub support: Option<serde_json::Value>,
+
     #[serde(flatten)]
     pub extra_fields: BTreeMap<String, serde_json::Value>,
 }
@@ -188,6 +194,8 @@ mod tests {
             install_path: None,
             autoload: None,
             aliases: vec![],
+            homepage: None,
+            support: None,
             extra_fields: BTreeMap::new(),
         }
     }
@@ -329,4 +337,28 @@ mod tests {
         assert_eq!(loaded.packages[0].name, "monolog/monolog");
         assert_eq!(loaded.packages[0].version, "3.8.0");
     }
+
+    #[test]
+    fn test_homepage_and_support_roundtrip() {
+        let json = r#"{
+            "packages": [
+                {
+                    "name": "vendor/pkg",
+                    "version": "1.0.0",
+                    "homepage": "https://vendor.example.com",
+                    "support": {"source": "https://github.com/vendor/pkg"}
+                }
+            ]
+        }"#;
+        let installed = InstalledPackages::from_json_str(json).unwrap();
+        let pkg = &installed.packages[0];
+        assert_eq!(pkg.homepage.as_deref(), Some("https://vendor.example.com"));
+        assert_eq!(
+            pkg.support
+                .as_ref()
+                .and_then(|s| s.get("source"))
+                .and_then(|s| s.as_str()),
+            Some("https://github.com/vendor/pkg")
+        );
+    }
 }