Read cached metadata for installed Git plugins (#20825)

## Summary
- Populate `plugin/list` interface metadata for installed Git-sourced
marketplace plugins from the active cached plugin bundle.
- Preserve marketplace category precedence so list behavior matches
`plugin/read`.
- Keep existing fallback behavior when the cache or manifest is missing
or invalid.

## Test Plan
- `cd codex-rs && just fmt`
- `cd codex-rs && cargo test -p codex-core-plugins
list_marketplaces_installed_git_source_reads_metadata_from_cache_without_cloning`
- `cd codex-rs && cargo test -p codex-app-server
plugin_list_returns_installed_git_source_interface_from_cache`
- `cd codex-rs && just fix -p codex-core-plugins`
- `cd codex-rs && just fix -p codex-app-server`
- `git diff --check`

Server-truth check: OpenAI monorepo app-server generated types already
expose `PluginSummary.interface`, and the webview consumes it for plugin
cards. This PR keeps the protocol/schema unchanged and fills the
existing field from the cached installed bundle for Git-backed
cross-repo plugins.

codex-rs/app-server/tests/suite/v2/plugin_list.rs

@@ -1141,6 +1141,124 @@ async fn plugin_list_accepts_legacy_string_default_prompt() -> Result<()> {
     Ok(())
 }
 
+#[tokio::test]
+async fn plugin_list_returns_installed_git_source_interface_from_cache() -> Result<()> {
+    let codex_home = TempDir::new()?;
+    let repo_root = TempDir::new()?;
+    let missing_remote_repo = repo_root.path().join("missing-remote-plugin-repo");
+    let missing_remote_repo_url = url::Url::from_directory_path(&missing_remote_repo)
+        .unwrap()
+        .to_string();
+    std::fs::create_dir_all(repo_root.path().join(".git"))?;
+    std::fs::create_dir_all(repo_root.path().join(".agents/plugins"))?;
+    std::fs::write(
+        repo_root.path().join(".agents/plugins/marketplace.json"),
+        format!(
+            r#"{{
+  "name": "debug",
+  "plugins": [
+    {{
+      "name": "toolkit",
+      "source": {{
+        "source": "git-subdir",
+        "url": "{missing_remote_repo_url}",
+        "path": "plugins/toolkit"
+      }},
+      "category": "Developer Tools"
+    }}
+  ]
+}}"#
+        ),
+    )?;
+    let cached_plugin_root = codex_home.path().join("plugins/cache/debug/toolkit/local");
+    std::fs::create_dir_all(cached_plugin_root.join(".codex-plugin"))?;
+    std::fs::write(
+        cached_plugin_root.join(".codex-plugin/plugin.json"),
+        r##"{
+  "name": "toolkit",
+  "interface": {
+    "displayName": "Toolkit",
+    "shortDescription": "Search cached data",
+    "category": "Cached Category",
+    "brandColor": "#3B82F6",
+    "composerIcon": "./assets/icon.png",
+    "logo": "./assets/logo.png"
+  }
+}"##,
+    )?;
+    std::fs::write(
+        codex_home.path().join("config.toml"),
+        r#"[features]
+plugins = true
+
+[plugins."toolkit@debug"]
+enabled = true
+"#,
+    )?;
+
+    let mut mcp = McpProcess::new(codex_home.path()).await?;
+    timeout(DEFAULT_TIMEOUT, mcp.initialize()).await??;
+
+    let request_id = mcp
+        .send_plugin_list_request(PluginListParams {
+            cwds: Some(vec![AbsolutePathBuf::try_from(repo_root.path())?]),
+            marketplace_kinds: None,
+        })
+        .await?;
+
+    let response: JSONRPCResponse = timeout(
+        DEFAULT_TIMEOUT,
+        mcp.read_stream_until_response_message(RequestId::Integer(request_id)),
+    )
+    .await??;
+    let response: PluginListResponse = to_response(response)?;
+
+    let plugin = response
+        .marketplaces
+        .iter()
+        .flat_map(|marketplace| marketplace.plugins.iter())
+        .find(|plugin| plugin.name == "toolkit")
+        .expect("expected toolkit entry");
+
+    assert_eq!(plugin.id, "toolkit@debug");
+    assert_eq!(plugin.installed, true);
+    assert_eq!(plugin.enabled, true);
+    assert_eq!(
+        plugin.source,
+        PluginSource::Git {
+            url: missing_remote_repo_url,
+            path: Some("plugins/toolkit".to_string()),
+            ref_name: None,
+            sha: None,
+        }
+    );
+    let interface = plugin
+        .interface
+        .as_ref()
+        .expect("expected cached plugin interface");
+    assert_eq!(interface.display_name.as_deref(), Some("Toolkit"));
+    assert_eq!(
+        interface.short_description.as_deref(),
+        Some("Search cached data")
+    );
+    assert_eq!(interface.category.as_deref(), Some("Developer Tools"));
+    assert_eq!(interface.brand_color.as_deref(), Some("#3B82F6"));
+    let canonical_cached_plugin_root = std::fs::canonicalize(&cached_plugin_root)?;
+    assert_eq!(
+        interface.composer_icon,
+        Some(AbsolutePathBuf::try_from(
+            canonical_cached_plugin_root.join("assets/icon.png")
+        )?)
+    );
+    assert_eq!(
+        interface.logo,
+        Some(AbsolutePathBuf::try_from(
+            canonical_cached_plugin_root.join("assets/logo.png")
+        )?)
+    );
+    Ok(())
+}
+
 #[tokio::test]
 async fn app_server_startup_remote_plugin_sync_runs_once() -> Result<()> {
     let codex_home = TempDir::new()?;

codex-rs/core-plugins/src/manager.rs

@@ -1196,19 +1196,37 @@ impl PluginsManager {
                         if !self.restriction_product_matches(plugin.policy.products.as_deref()) {
                             return None;
                         }
+                        let installed = installed_plugins.contains(&plugin_key);
+                        let enabled = enabled_plugins.contains(&plugin_key);
+                        let mut interface = plugin.interface;
+                        if installed
+                            && matches!(&plugin.source, MarketplacePluginSource::Git { .. })
+                            && let Ok(plugin_id) =
+                                PluginId::new(plugin.name.clone(), marketplace_name.clone())
+                            && let Some(plugin_root) = self.store.active_plugin_root(&plugin_id)
+                            && let Some(manifest) = load_plugin_manifest(plugin_root.as_path())
+                        {
+                            let marketplace_category = interface
+                                .as_ref()
+                                .and_then(|interface| interface.category.clone());
+                            interface = plugin_interface_with_marketplace_category(
+                                manifest.interface,
+                                marketplace_category,
+                            );
+                        }
 
                         Some(ConfiguredMarketplacePlugin {
                             // Enabled state is keyed by `<plugin>@<marketplace>`, so duplicate
                             // plugin entries from duplicate marketplace files intentionally
                             // resolve to the first discovered source.
-                            id: plugin_key.clone(),
-                            installed: installed_plugins.contains(&plugin_key),
-                            enabled: enabled_plugins.contains(&plugin_key),
+                            id: plugin_key,
+                            installed,
+                            enabled,
                             name: plugin.name,
                             source: plugin.source,
                             policy: plugin.policy,
-                            interface: plugin.interface,
                             keywords: plugin.keywords,
+                            interface,
                         })
                     })
                     .collect::<Vec<_>>();

codex-rs/core-plugins/src/manager_tests.rs

@@ -2039,6 +2039,116 @@ enabled = false
     );
 }
 
+#[tokio::test]
+async fn list_marketplaces_installed_git_source_reads_metadata_from_cache_without_cloning() {
+    let tmp = tempfile::tempdir().unwrap();
+    let repo_root = tmp.path().join("repo");
+    let missing_remote_repo = tmp.path().join("missing-remote-plugin-repo");
+    let missing_remote_repo_url = url::Url::from_directory_path(&missing_remote_repo)
+        .unwrap()
+        .to_string();
+    fs::create_dir_all(repo_root.join(".git")).unwrap();
+    write_file(
+        &repo_root.join(".agents/plugins/marketplace.json"),
+        &format!(
+            r#"{{
+  "name": "debug",
+  "plugins": [
+    {{
+      "name": "toolkit",
+      "source": {{
+        "source": "git-subdir",
+        "url": "{missing_remote_repo_url}",
+        "path": "plugins/toolkit"
+      }},
+      "category": "Developer Tools"
+    }}
+  ]
+}}"#
+        ),
+    );
+    let cached_plugin_root = tmp.path().join("plugins/cache/debug/toolkit/local");
+    write_file(
+        &cached_plugin_root.join(".codex-plugin/plugin.json"),
+        r##"{
+  "name": "toolkit",
+  "interface": {
+    "displayName": "Toolkit",
+    "shortDescription": "Search cached data",
+    "category": "Cached Category",
+    "brandColor": "#3B82F6",
+    "composerIcon": "./assets/icon.png",
+    "logo": "./assets/logo.png",
+    "screenshots": ["./assets/screenshot.png"]
+  }
+}"##,
+    );
+    write_file(
+        &tmp.path().join(CONFIG_TOML_FILE),
+        r#"[features]
+plugins = true
+
+[plugins."toolkit@debug"]
+enabled = true
+"#,
+    );
+
+    let config = load_config(tmp.path(), &repo_root).await;
+    let marketplaces = PluginsManager::new(tmp.path().to_path_buf())
+        .list_marketplaces_for_config(&config, &[AbsolutePathBuf::try_from(repo_root).unwrap()])
+        .unwrap()
+        .marketplaces;
+
+    let marketplace = marketplaces
+        .into_iter()
+        .find(|marketplace| marketplace.name == "debug")
+        .expect("debug marketplace should be listed");
+
+    assert_eq!(
+        marketplace.plugins,
+        vec![ConfiguredMarketplacePlugin {
+            id: "toolkit@debug".to_string(),
+            name: "toolkit".to_string(),
+            source: MarketplacePluginSource::Git {
+                url: missing_remote_repo_url,
+                path: Some("plugins/toolkit".to_string()),
+                ref_name: None,
+                sha: None,
+            },
+            policy: MarketplacePluginPolicy {
+                installation: MarketplacePluginInstallPolicy::Available,
+                authentication: MarketplacePluginAuthPolicy::OnInstall,
+                products: None,
+            },
+            interface: Some(PluginManifestInterface {
+                display_name: Some("Toolkit".to_string()),
+                short_description: Some("Search cached data".to_string()),
+                category: Some("Developer Tools".to_string()),
+                brand_color: Some("#3B82F6".to_string()),
+                composer_icon: Some(
+                    AbsolutePathBuf::try_from(cached_plugin_root.join("assets/icon.png")).unwrap(),
+                ),
+                logo: Some(
+                    AbsolutePathBuf::try_from(cached_plugin_root.join("assets/logo.png")).unwrap(),
+                ),
+                screenshots: vec![
+                    AbsolutePathBuf::try_from(cached_plugin_root.join("assets/screenshot.png"))
+                        .unwrap(),
+                ],
+                ..Default::default()
+            }),
+            keywords: Vec::new(),
+            installed: true,
+            enabled: true,
+        }]
+    );
+    assert!(
+        !tmp.path()
+            .join("plugins/.marketplace-plugin-source-staging")
+            .exists()
+    );
+}
+
 #[tokio::test]
 async fn sync_plugins_from_remote_returns_default_when_feature_disabled() {
     let tmp = tempfile::tempdir().unwrap();