feat(FN-3714): add WhatsApp chat plugin with plugin discovery and install U

Adds a WhatsApp chat plugin (`plugins/fusion-plugin-whatsapp-chat/`) as the first bundled plugin, including the plugin package with UI rendering, dashboard plugin manager integration, CLI bundling support, and plugin route runtime context. Also updates documentation to cover plugin management and ap

Fusion-Task-Id: FN-3714

packages/dashboard/src/plugin-routes.ts

@@ -23,7 +23,7 @@ import type {
   PluginStore,
   PluginContext,
 } from "@fusion/core";
-import { validatePluginManifest } from "@fusion/core";
+import { getCreateAiSessionFactory, validatePluginManifest } from "@fusion/core";
 import {
   ApiError,
   badRequest,
@@ -547,12 +547,34 @@ export function createPluginRouter(
             ? (req.body as { projectId: string }).projectId
             : undefined);
         const scopedStore = projectId ? await getOrCreateProjectStore(projectId) : null;
+        const taskStore = scopedStore ?? defaultTaskStore ?? ({} as import("@fusion/core").TaskStore);
+
+        let settings: Record<string, unknown> = {};
+        const scopedPluginStore = scopedStore?.getPluginStore?.();
+        if (scopedPluginStore) {
+          try {
+            const scopedPlugin = await scopedPluginStore.getPlugin(pluginId);
+            settings = scopedPlugin.settings;
+          } catch {
+            // Fall back to default store plugin settings when project-scoped plugin record is unavailable.
+          }
+        }
+        if (!scopedPluginStore || Object.keys(settings).length === 0) {
+          try {
+            const pluginRecord = await pluginStore.getPlugin(pluginId);
+            settings = pluginRecord.settings;
+          } catch {
+            // Keep empty settings when plugin store record isn't available.
+          }
+        }
+
+        const createAiSession = await getCreateAiSessionFactory();
 
         // Create a minimal context for the handler
         const ctx: PluginContext = {
           pluginId,
-          taskStore: scopedStore ?? defaultTaskStore ?? ({} as import("@fusion/core").TaskStore),
-          settings: {},
+          taskStore,
+          settings,
           logger: {
             info: (...args: unknown[]) => console.log(`[plugin:${pluginId}]`, ...args),
             warn: (...args: unknown[]) => console.warn(`[plugin:${pluginId}]`, ...args),
@@ -564,6 +586,7 @@ export function createPluginRouter(
             },
           },
           emitEvent: () => {},
+          createAiSession,
         };
 
         // Call the route handler with Express Request cast to unknown