feat(backend): système de plugins — domaine, application, infrastructure (#43)

Lots B1-B4 : modèle de domaine des plugins (manifeste, capacités menus/layouts/MCP),
port et registre applicatif, chargement/validation en infrastructure, exposition DTO
et commandes Tauri. Tests cargo verts.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

crates/domain/src/ports.rs

@@ -49,6 +49,11 @@ use crate::model_server::{
     HfModelRef, LocalModelServerConfig, ModelPath, ModelServerEndpoint, ModelServerStatus,
 };
 use crate::permission::ProjectPermissions;
+use crate::plugin::{
+    ContentHash, PluginBundleUrl, PluginId, PluginManifest, PluginMcpServerSpec,
+    PluginMcpStatusSet, PluginPackageRef, PluginRegistry, RelativePath, RemovalOutcome,
+    StagedPluginPackage,
+};
 use crate::profile::{AgentProfile, EmbedderProfile};
 use crate::project::{Project, ProjectPath};
 use crate::remote::RemoteKind;
@@ -279,6 +284,166 @@ impl RemotePath {
     }
 }
 
+/// Opaque local path supplied by a driving adapter.
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+pub struct LocalPath(pub String);
+
+impl LocalPath {
+    /// Wraps a raw path.
+    #[must_use]
+    pub fn new(p: impl Into<String>) -> Self {
+        Self(p.into())
+    }
+
+    /// Returns the path as a string slice.
+    #[must_use]
+    pub fn as_str(&self) -> &str {
+        &self.0
+    }
+}
+
+/// Raw manifest bytes.
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct PluginManifestBytes {
+    /// Bytes of `idea-plugin.json`.
+    pub bytes: Vec<u8>,
+}
+
+/// Plugin package store errors.
+#[derive(Debug, Clone, PartialEq, Eq, Error)]
+pub enum PluginStoreError {
+    /// Package was not found.
+    #[error("plugin package not found")]
+    NotFound,
+    /// Invalid input/source.
+    #[error("invalid plugin package: {0}")]
+    Invalid(String),
+    /// I/O error.
+    #[error("plugin package I/O error: {0}")]
+    Io(String),
+    /// Serialization or archive error.
+    #[error("plugin package format error: {0}")]
+    Format(String),
+}
+
+/// Plugin registry errors.
+#[derive(Debug, Clone, PartialEq, Eq, Error)]
+pub enum PluginRegistryError {
+    /// I/O error.
+    #[error("plugin registry I/O error: {0}")]
+    Io(String),
+    /// Serialization error.
+    #[error("plugin registry serialization error: {0}")]
+    Serialization(String),
+}
+
+/// Manifest validation errors.
+#[derive(Debug, Clone, PartialEq, Eq, Error)]
+pub enum PluginManifestError {
+    /// Invalid JSON.
+    #[error("invalid plugin manifest JSON: {0}")]
+    Json(String),
+    /// Invalid manifest data.
+    #[error("invalid plugin manifest: {0}")]
+    Invalid(String),
+    /// Incompatible engine.
+    #[error("incompatible IdeA engine: {0}")]
+    IncompatibleEngine(String),
+}
+
+/// Plugin MCP errors.
+#[derive(Debug, Clone, PartialEq, Eq, Error)]
+pub enum PluginMcpError {
+    /// Process/supervisor failure.
+    #[error("plugin MCP error: {0}")]
+    Process(String),
+}
+
+/// Store for installed plugin packages under the global app data directory.
+#[async_trait]
+pub trait PluginPackageStore: Send + Sync {
+    /// Lists committed package roots.
+    async fn list_installed(&self) -> Result<Vec<PluginPackageRef>, PluginStoreError>;
+
+    /// Reads `idea-plugin.json` from a package root.
+    async fn read_manifest(
+        &self,
+        package: &PluginPackageRef,
+    ) -> Result<PluginManifestBytes, PluginStoreError>;
+
+    /// Stages an archive for validation.
+    async fn install_from_archive(
+        &self,
+        archive: &LocalPath,
+    ) -> Result<StagedPluginPackage, PluginStoreError>;
+
+    /// Stages a directory snapshot for validation.
+    async fn install_from_directory(
+        &self,
+        dir: &LocalPath,
+    ) -> Result<StagedPluginPackage, PluginStoreError>;
+
+    /// Commits a staged install into `installed/<pluginId>`.
+    async fn commit_install(
+        &self,
+        staged: StagedPluginPackage,
+        plugin_id: &PluginId,
+    ) -> Result<PluginPackageRef, PluginStoreError>;
+
+    /// Removes a committed package.
+    async fn remove_package(
+        &self,
+        plugin_id: &PluginId,
+    ) -> Result<RemovalOutcome, PluginStoreError>;
+
+    /// Builds a protocol URL for a bundle/asset.
+    fn bundle_url(
+        &self,
+        plugin_id: &PluginId,
+        entry: &RelativePath,
+        hash: &ContentHash,
+    ) -> Result<PluginBundleUrl, PluginStoreError>;
+
+    /// Returns the global application data directory label when the adapter can
+    /// expose it for manifest variable substitution.
+    fn app_data_dir_label(&self) -> Option<String> {
+        None
+    }
+}
+
+/// Store for the global plugin registry.
+#[async_trait]
+pub trait PluginRegistryStore: Send + Sync {
+    /// Loads the registry, returning an empty document if missing.
+    async fn load_registry(&self) -> Result<PluginRegistry, PluginRegistryError>;
+
+    /// Persists the registry.
+    async fn save_registry(&self, registry: &PluginRegistry) -> Result<(), PluginRegistryError>;
+}
+
+/// Manifest parser and validator.
+pub trait PluginManifestValidator: Send + Sync {
+    /// Validates raw manifest bytes.
+    fn validate(
+        &self,
+        bytes: &[u8],
+        package_root: &PluginPackageRef,
+    ) -> Result<PluginManifest, PluginManifestError>;
+}
+
+/// Supervisor for external MCP servers declared by plugins.
+#[async_trait]
+pub trait PluginMcpSupervisor: Send + Sync {
+    /// Reconciles the desired active server set.
+    async fn reconcile(
+        &self,
+        active_servers: Vec<PluginMcpServerSpec>,
+    ) -> Result<PluginMcpStatusSet, PluginMcpError>;
+
+    /// Stops every server owned by one plugin.
+    async fn stop_plugin(&self, plugin_id: &PluginId) -> Result<(), PluginMcpError>;
+}
+
 /// A single directory entry returned by [`FileSystem::list`].
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct DirEntry {