Major improvements to build system, authentication flow, and user experience:

Build System:
- Configure common source set for shared security/network code
- Fix compilation errors by properly organizing source sets
- Add Mod Menu integration for configuration GUI

Client-Side Authentication:
- Replace Slingshot with official Bluesky identity resolution APIs
- Use com.atproto.identity.resolveHandle for standard handle resolution
- Improve error handling and user feedback
- Add /atproto config and /atproto gui commands

New Features:
- Add AtProtoConfigScreen for GUI-based authentication
- Integrate with Mod Menu for easy access to settings
- No-typing-required login flow with visual feedback
- Client-side password handling with security notices

Code Organization:
- Move security classes to src/common/kotlin/com/jollywhoppers/security/
- Move network classes to src/common/kotlin/com/jollywhoppers/network/
- Organize server code under atproto/server/ package
- Organize client code under atproto/client/ package
- Move example code to docs/examples/

This update resolves all compilation errors and provides a much better
user experience with GUI-based authentication.

Updates README and build configuration from 0.0.1 to 0.3.0 to match the
addition of client-side authentication, hardened security, and the
RecordManager API. Project remains alpha and pre-1.0.

Shift AT Protocol authentication fully to the client for improved security.

Client now handles login and session creation locally, with verified sessions
sent to the server via network packets. Server-side login commands are removed
and deprecated APIs are marked accordingly.

Adds client-side initialisation, commands, and packet handlers, and updates
server session management to store verified client-authenticated sessions.

Also updates RecordManager and examples to use explicit kotlinx.serialization
serializers, improving type safety and avoiding reified Serializable bounds.

Introduce a full-featured RecordManager for AT Protocol repositories.

Adds type-safe CRUD operations for records, including create, read, list,
update (upsert), and delete, with support for pagination, compare-and-swap,
and atomic batch writes via applyWrites.

Includes utility helpers for TID generation and AT URI parsing, plus
serialisable request/response models.

Also adds a comprehensive examples module demonstrating real-world usage
patterns (stats syncing, achievements, profiles, safe updates, pagination,
and atomic transactions) to serve as reference documentation.

- Encrypt session data at rest using AES-256-GCM
- Add rate limiting and temporary lockouts for auth attempts
- Introduce security audit logging for sensitive operations
- Harden HTTP client against SSRF and DNS rebinding
- Enforce restricted file permissions and atomic writes
- Improve error sanitisation to avoid leaking sensitive details
- Update README with security features, config details, and roadmap

Add core AT Protocol integration with Slingshot-based PDS resolution,
player identity linking, authenticated sessions, and in-game commands.
Includes session persistence, token refresh, and expanded documentation.