refactor: fix directory structure and namespaces for webman conventions

- Rename directories to lowercase: Controller→controller, Model→model, Service→service, Util→util, Bootstrap→bootstrap
- Update all namespaces from App\Xxx to app\xxx (webman convention)
- Update all import statements across the codebase
- Update route.php to use lowercase namespaces
- Remove unused CompanyFeishuApp model
- Comment out unimplemented controller routes

Following webman 2.x framework conventions:
- Models: app\model\{ClassName}
- Controllers: app\controller\{ClassName}
- Services: app\service\{ClassName}
- Utils: app\util\{ClassName}
- Middleware: app\middleware\{ClassName}

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

backend/app/model/Company.php

@@ -0,0 +1,96 @@
+<?php
+
+namespace app\model;
+
+use support\Model;
+
+class Company extends Model
+{
+    protected $table = 'companies';
+
+    protected $fillable = [
+        'name',
+        'abbr',
+        'tenant_key',
+        'sort',
+        'status',
+        'feishu_enabled',
+    ];
+
+    protected $casts = [
+        'sort' => 'integer',
+        'status' => 'integer',
+        'feishu_enabled' => 'boolean',
+        'created_at' => 'datetime',
+        'updated_at' => 'datetime',
+    ];
+
+    /**
+     * 关联用户
+     */
+    public function users()
+    {
+        return $this->hasMany(User::class, 'company_id');
+    }
+
+    /**
+     * 获取启用的公司
+     */
+    public function scopeActive($query)
+    {
+        return $query->where('status', 1);
+    }
+
+    /**
+     * 根据租户Key查找
+     */
+    public function scopeByTenantKey($query, string $tenantKey)
+    {
+        return $query->where('tenant_key', $tenantKey);
+    }
+
+    /**
+     * 根据缩写查找
+     */
+    public function scopeByAbbr($query, string $abbr)
+    {
+        return $query->where('abbr', $abbr);
+    }
+
+    /**
+     * 搜索公司
+     */
+    public function scopeSearch($query, ?string $keyword)
+    {
+        if (!$keyword) {
+            return $query;
+        }
+
+        return $query->where(function ($q) use ($keyword) {
+            $q->where('name', 'like', "%{$keyword}%")
+                ->orWhere('abbr', 'like', "%{$keyword}%");
+        });
+    }
+
+    /**
+     * 获取默认飞书应用配置
+     */
+    public function getDefaultFeishuApp(): ?array
+    {
+        $sql = "SELECT * FROM company_feishu_apps WHERE company_id = ? AND system_id = 1 AND status = 1 ORDER BY sort ASC LIMIT 1";
+        $stmt = \app\util\Db::connection()->getPdo()->prepare($sql);
+        $stmt->execute([$this->id]);
+        return $stmt->fetch(\PDO::FETCH_ASSOC);
+    }
+
+    /**
+     * 获取所有飞书应用配置
+     */
+    public function getFeishuApps(): array
+    {
+        $sql = "SELECT * FROM company_feishu_apps WHERE company_id = ? AND status = 1 ORDER BY sort";
+        $stmt = \app\util\Db::connection()->getPdo()->prepare($sql);
+        $stmt->execute([$this->id]);
+        return $stmt->fetchAll(\PDO::FETCH_ASSOC);
+    }
+}