feat(plugins): paramètres projet plugins + attribution skills/tools aux agents — #282 (manifeste accepte contributes.skills IdeA-native multi-harness; store .ideai/project-plugins.json v1: enable plugin par projet + assignments skills/tools par agent; refs + use cases settings/assign/unassign; resolver skills pour idea_skill_read et injection catalogue lancement agent; permissions MCP dynamiques projetées par harness Claude Code/Codex/OpenCode; tombstones uninstall, hot reload recalcule catalogue et marque assignments cassés; frontend: Settings projet Plugins, détail capabilities, attribution agent, catalogue permissions; bump pointeur IdeaSDK 6eb8db3; QA verte: cargo test -p application, project_plugin_settings 3/3, dto_plugins 2/2, structured_launch_d3 26/26, catalogue mcp 7/7, frontend 5 tests ProjectPluginSettings/plugin, npm build frontend)

crates/infrastructure/src/plugin/mod.rs

@@ -155,6 +155,21 @@ impl PluginPackageStore for FsPluginPackageStore {
         Ok(PluginManifestBytes { bytes })
     }
 
+    async fn read_installed_file(
+        &self,
+        plugin_id: &PluginId,
+        path: &RelativePath,
+    ) -> Result<Vec<u8>, PluginStoreError> {
+        let resolved = self.resolve_asset_path(plugin_id, path)?;
+        fs::read(resolved).map_err(|e| {
+            if e.kind() == io::ErrorKind::NotFound {
+                PluginStoreError::NotFound
+            } else {
+                PluginStoreError::Io(e.to_string())
+            }
+        })
+    }
+
     async fn install_from_archive(
         &self,
         archive: &LocalPath,