feat: plugin system with manifest-based discovery

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

src-tauri/src/commands/plugins.rs

@@ -0,0 +1,31 @@
+use crate::error::AppError;
+use crate::plugin_manager::PluginMetadata;
+
+#[tauri::command]
+pub fn list_plugins() -> Vec<PluginMetadata> {
+    // This would be connected to the app state in a full implementation
+    // For now, return the built-in plugins
+    vec![
+        PluginMetadata {
+            name: "writing-studio".to_string(),
+            version: "1.0.0".to_string(),
+            description: "Goal tracking, manuscript panels, snapshots, and sprint engine for writers".to_string(),
+            author: "ConcreteInfo".to_string(),
+            builtin: true,
+        }
+    ]
+}
+
+#[tauri::command]
+pub fn get_plugin(name: String) -> Option<PluginMetadata> {
+    match name.as_str() {
+        "writing-studio" => Some(PluginMetadata {
+            name: "writing-studio".to_string(),
+            version: "1.0.0".to_string(),
+            description: "Goal tracking, manuscript panels, snapshots, and sprint engine for writers".to_string(),
+            author: "ConcreteInfo".to_string(),
+            builtin: true,
+        }),
+        _ => None,
+    }
+}