feat(frontend): système de plugins — runtime, menus, layouts custom (#43)

Lots F1-F4 : runtime de chargement/registre plugin, extension des menus
existants, panneau de gestion des plugins, types de layout custom
(sélecteur, fallback, cellule dédiée) branchés sur le port plugin.
Suite npm typecheck/test verte (947/947).

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

frontend/src/adapters/mock/index.ts

@@ -38,6 +38,13 @@ import type {
   PairedDevice,
   PairingCode,
   PermissionSet,
+  PluginAdmin,
+  PluginContributionSummary,
+  PluginInstallResult,
+  PluginLifecycleState,
+  PluginReview,
+  PluginRuntimeContributionCatalog,
+  PluginUninstallResult,
   Project,
   ProjectMcpToolPermissions,
   ProjectPermissions,
@@ -88,8 +95,10 @@ import type {
   ProfileGateway,
   ProjectGateway,
   PermissionGateway,
+  PluginGateway,
   ReattachResult,
   RemoteGateway,
+  ReviewPluginPackageInput,
   SkillGateway,
   StoppedLiveAgent,
   SystemGateway,
@@ -184,6 +193,11 @@ export class MockSystemGateway implements SystemGateway {
     return "/home/user/mock-project";
   }
 
+  /** Returns a deterministic fake path — never opens a native dialog. */
+  async pickArchiveFile(): Promise<string | null> {
+    return "/home/user/mock-plugin.ideaplug";
+  }
+
   private exitGuardListeners = new Set<(state: AppExitWorkGuardState) => void>();
   /** Count of `confirmAppExit()` calls, for test assertions. */
   confirmAppExitCallCount = 0;
@@ -2923,6 +2937,114 @@ function mostRestrictive(
   return rank[agent] >= rank[fallback] ? agent : fallback;
 }
 
+/**
+ * In-memory plugin store (ticket #43, F1). Mirrors the carnet contract closely
+ * enough to develop/test F1-F4 without the backend (B1-B4, landing in
+ * parallel): review before commit, install/enable/disable/uninstall, and a
+ * runtime catalog that only ever lists `enabled && !pendingUninstall` plugins.
+ */
+export class MockPluginGateway implements PluginGateway {
+  private plugins: PluginAdmin[] = [];
+  private seq = 0;
+
+  private summaryFor(_pluginId: string): PluginContributionSummary {
+    return { topLevelMenus: 0, menuItems: 0, layouts: 0, mcpServers: 0 };
+  }
+
+  /** Test/dev helper: seed a plugin directly, bypassing install. */
+  _seedPlugin(plugin: PluginAdmin): void {
+    this.plugins.push(plugin);
+  }
+
+  async listPlugins(): Promise<PluginAdmin[]> {
+    return structuredClone(this.plugins);
+  }
+
+  async reviewPackage(input: ReviewPluginPackageInput): Promise<PluginReview> {
+    this.seq += 1;
+    const label = input.path.split("/").pop() ?? input.path;
+    return {
+      id: `mock.plugin.${this.seq}`,
+      displayName: label.replace(/\.(ideaplug|zip|vsix)$/i, ""),
+      publisher: "Mock Publisher",
+      version: "0.1.0",
+      description: `Reviewed from ${input.sourceKind}: ${input.path}`,
+      trustLevel: "full",
+      contributionSummary: this.summaryFor(`mock.plugin.${this.seq}`),
+      issues: [],
+      installable: true,
+    };
+  }
+
+  private async install(
+    sourceKind: "archive" | "directory",
+    path: string,
+  ): Promise<PluginInstallResult> {
+    this.seq += 1;
+    const label = path.split("/").pop() ?? path;
+    const plugin: PluginAdmin = {
+      id: `mock.plugin.${this.seq}`,
+      displayName: label.replace(/\.(ideaplug|zip|vsix)$/i, ""),
+      publisher: "Mock Publisher",
+      version: "0.1.0",
+      sourceKind,
+      sourceLabel: path,
+      lifecycleState: "enabled",
+      enabled: true,
+      pendingUninstall: false,
+      restartRequired: true,
+      trustLevel: "full",
+      contributionSummary: this.summaryFor(`mock.plugin.${this.seq}`),
+    };
+    this.plugins.push(plugin);
+    return { plugin: structuredClone(plugin), restartRequired: true };
+  }
+
+  installFromArchive(path: string): Promise<PluginInstallResult> {
+    return this.install("archive", path);
+  }
+
+  installFromDirectory(path: string): Promise<PluginInstallResult> {
+    return this.install("directory", path);
+  }
+
+  async setEnabled(pluginId: string, enabled: boolean): Promise<PluginAdmin> {
+    const plugin = this.plugins.find((p) => p.id === pluginId);
+    if (!plugin) {
+      const err: GatewayError = { code: "NOT_FOUND", message: `plugin ${pluginId} not found` };
+      throw err;
+    }
+    const state: PluginLifecycleState = enabled ? "enabled" : "disabled";
+    plugin.enabled = enabled;
+    plugin.lifecycleState = state;
+    plugin.restartRequired = true;
+    return structuredClone(plugin);
+  }
+
+  async uninstall(pluginId: string): Promise<PluginUninstallResult> {
+    const idx = this.plugins.findIndex((p) => p.id === pluginId);
+    if (idx === -1) {
+      const err: GatewayError = { code: "NOT_FOUND", message: `plugin ${pluginId} not found` };
+      throw err;
+    }
+    this.plugins.splice(idx, 1);
+    return { pluginId, restartRequired: true };
+  }
+
+  async listRuntimeContributions(): Promise<PluginRuntimeContributionCatalog> {
+    // Only enabled, non-pending-uninstall plugins are loadable at bootstrap
+    // (carnet §1.3) — the mock has no bundle to actually import, so this
+    // starts empty; tests seed `plugins` on `PluginRuntimeContributionCatalog`
+    // directly via a `MockPluginGateway` subclass/test double when a loader
+    // round-trip is needed.
+    return { plugins: [] };
+  }
+
+  async openPluginsFolder(_pluginId?: string): Promise<void> {
+    // No filesystem in the mock — no-op.
+  }
+}
+
 /** Builds the full set of mock gateways. */
 export function createMockGateways(): Gateways {
   const agentGateway = new MockAgentGateway();
@@ -2951,6 +3073,7 @@ export function createMockGateways(): Gateways {
     window: new MockWindowGateway(),
     focusedProject: new MockFocusedProjectGateway(),
     uiPreferences: new MockUiPreferencesGateway(),
+    plugin: new MockPluginGateway(),
   };
 }