Refactor genai package to new modular interface

Reorganized the genai package by removing legacy LLM-related files and introducing a new modular interface under the 'interface' directory. Added provider-specific model classes, centralized constants, and updated the example to use the new API and data structures. Updated exports in genai.dart and improved dependency management.

packages/genai/lib/utils/model_manager.dart

@@ -0,0 +1,97 @@
+import 'dart:convert';
+import 'package:better_networking/better_networking.dart';
+import 'package:flutter/foundation.dart';
+import '../consts.dart';
+import '../interface/interface.dart';
+import '../models/models.dart';
+
+class ModelManager {
+  static Future<AvailableModels?> fetchModelsFromRemote({
+    String? remoteURL,
+  }) async {
+    try {
+      final (resp, _, _) = await sendHttpRequest(
+        'FETCH_MODELS',
+        APIType.rest,
+        HttpRequestModel(
+          url: remoteURL ?? kModelRemoteUrl,
+          method: HTTPVerb.get,
+        ),
+      );
+      if (resp == null) {
+        debugPrint('fetchModelsFromRemote -> resp == null');
+      } else {
+        var remoteModels = availableModelsFromJson(resp.body);
+        return remoteModels;
+      }
+    } catch (e) {
+      debugPrint('fetchModelsFromRemote -> ${e.toString()}');
+    }
+    return null;
+  }
+
+  static Future<AvailableModels> fetchAvailableModels({
+    String? ollamaUrl,
+  }) async {
+    try {
+      final oM = await fetchInstalledOllamaModels(ollamaUrl: ollamaUrl);
+      if (oM != null) {
+        List<AIModelProvider> l = [];
+        for (var prov in kAvailableModels.modelProviders) {
+          if (prov.providerId == ModelAPIProvider.ollama) {
+            l.add(
+              prov.copyWith(
+                providerId: prov.providerId,
+                providerName: prov.providerName,
+                sourceUrl: prov.sourceUrl,
+                models: oM,
+              ),
+            );
+          } else {
+            l.add(prov);
+          }
+        }
+        return kAvailableModels.copyWith(
+          version: kAvailableModels.version,
+          modelProviders: l,
+        );
+      }
+    } catch (e) {
+      debugPrint('fetchAvailableModels -> ${e.toString()}');
+    }
+    return kAvailableModels;
+  }
+
+  static Future<List<Model>?> fetchInstalledOllamaModels({
+    String? ollamaUrl,
+  }) async {
+    // All available models
+    // final url = "${ollamaUrl ?? kBaseOllamaUrl}/api/tags";
+    // All loaded models
+    final url = "${ollamaUrl ?? kBaseOllamaUrl}/api/ps";
+
+    try {
+      final (resp, _, msg) = await sendHttpRequest(
+        'OLLAMA_FETCH',
+        APIType.rest,
+        HttpRequestModel(url: url, method: HTTPVerb.get),
+        noSSL: true,
+      );
+      // debugPrint("fetchInstalledOllamaModels -> $url -> ${resp?.body} -> $msg");
+      if (resp == null) {
+        return null;
+      }
+      final output = jsonDecode(resp.body);
+      final models = output['models'];
+      if (models == null) return [];
+      List<Model> ollamaModels = [];
+      for (final m in models) {
+        ollamaModels.add(Model(id: m['model'], name: m['name']));
+      }
+      return ollamaModels;
+    } catch (e) {
+      debugPrint('fetchInstalledOllamaModels -> ${e.toString()}');
+      return null;
+    }
+  }
+}