Add PDF reports, file uploads, admin auth, and comprehensive tests

Features:
- PDF service for generating task reports with ReportLab-style formatting
- Storage service for file uploads (local and S3-compatible)
- Admin authentication middleware with JWT support
- Admin user model and repository

Infrastructure:
- Updated Docker configuration for admin panel builds
- Email service enhancements for task notifications
- Updated router with admin and file upload routes
- Environment configuration updates

Tests:
- Unit tests for handlers (auth, residence, task)
- Unit tests for models (user, residence, task)
- Unit tests for repositories (user, residence, task)
- Unit tests for services (residence, task)
- Integration test setup
- Test utilities for mocking database and services

Database:
- Admin user seed data
- Updated test data seeds

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

internal/models/subscription.go

@@ -27,6 +27,7 @@ func (SubscriptionSettings) TableName() string {
 type UserSubscription struct {
 	BaseModel
 	UserID            uint             `gorm:"column:user_id;uniqueIndex;not null" json:"user_id"`
+	User              User             `gorm:"foreignKey:UserID" json:"-"`
 	Tier              SubscriptionTier `gorm:"column:tier;size:10;default:'free'" json:"tier"`
 
 	// In-App Purchase data