(feat) Agent persistence with message history

[rrr63]

1. StoreInterface

• Contract for storage implementations
• Methods: store(), load(), has(), delete(), clear()
• Allows custom implementations (database, Redis, sessions, etc.)

2. CacheStore -> First integration, to show how it works, indeed each user will make custom depending where they want to save

• File-based serialized storage
• Configurable path (default: ./doppar_ai_store)
• MD5-based filename generation

3. Agent Integration

• withStore(StoreInterface $store, ?string $key = null) - configure store
• store(string $key, mixed $response = null) - save messages + optional response
• loadMessages(string $key) - restore full history
• assistant(string $content) - add assistant role messages

$store = new CacheStore("./storage/doppar_ai_store");

// Set store in agent object
$agent->withStore($store);

// Save conversation
$res = $agent->send();
$agent->store('conversation-1', $res);

// Load and continue
$agent->loadMessages('conversation-1')
    ->prompt('Next question')
    ->send();

[techmahedy]

@rrr63 great, very good job. Very important feature

[techmahedy]

Nice to have this @rrr63 good job

[techmahedy]

Thanks @rrr63