feat(plugins): hot reload des plugins sans relancer IdeA — use case ReloadPlugin (invalidation registry/catalogue, resultat hashes+changed), tools MCP d'administration plugin agent-facing (mcp/plugins.rs + PluginToolProvider), evenement domaine plugin_reloaded relaye sur le wire (dto/events), exposition openai_tools rafraichie, wiring app-tauri — #271/#269 (QA verte #273: application 32, mcp_server 38, openai_tools 10, plugin_install_load 5, plugin 10, wire 1 — 96 tests ciblés; app-tauri compile sans desktop runtime)

crates/backend/src/dto.rs

@@ -199,6 +199,59 @@ impl From<application::PluginInstallResult> for PluginInstallResultDto {
     }
 }
 
+/// Plugin reload request DTO.
+#[derive(Debug, Clone, Deserialize)]
+#[serde(rename_all = "camelCase")]
+pub struct ReloadPluginDto {
+    /// Installed plugin id.
+    pub plugin_id: String,
+    /// Optional installed-hash concurrency guard.
+    pub expected_content_hash: Option<String>,
+}
+
+impl From<ReloadPluginDto> for application::ReloadPluginInput {
+    fn from(value: ReloadPluginDto) -> Self {
+        Self {
+            plugin_id: value.plugin_id,
+            expected_content_hash: value.expected_content_hash,
+        }
+    }
+}
+
+/// Plugin hot-reload result DTO.
+#[derive(Debug, Clone, Serialize, Deserialize)]
+#[serde(rename_all = "camelCase")]
+pub struct PluginReloadResultDto {
+    /// Reloaded plugin.
+    pub plugin: PluginAdminDto,
+    /// Previous content hash.
+    pub old_content_hash: String,
+    /// New content hash.
+    pub new_content_hash: String,
+    /// Whether the content changed.
+    pub changed: bool,
+    /// Runtime catalogue entry when active.
+    pub runtime_catalog_entry: Option<application::PluginRuntimePlugin>,
+    /// MCP status after reconciliation.
+    pub mcp_statuses: domain::PluginMcpStatusSet,
+    /// Non-fatal warnings.
+    pub warnings: Vec<String>,
+}
+
+impl From<application::PluginReloadResult> for PluginReloadResultDto {
+    fn from(value: application::PluginReloadResult) -> Self {
+        Self {
+            plugin: value.plugin.into(),
+            old_content_hash: value.old_content_hash,
+            new_content_hash: value.new_content_hash,
+            changed: value.changed,
+            runtime_catalog_entry: value.runtime_catalog_entry,
+            mcp_statuses: value.mcp_statuses,
+            warnings: value.warnings,
+        }
+    }
+}
+
 /// Plugin uninstall result DTO.
 #[derive(Debug, Clone, Serialize, Deserialize)]
 #[serde(rename_all = "camelCase")]