v3.0.3 Documentation Overhaul, Agent Skill & Auto-generated XDR types

This release brings three major improvements to the Stellar Flutter SDK: completely rewritten documentation with tested code examples, an agent skill for AI coding agents, and machine-generated XDR types from canonical Stellar .x definitions.

New documentation (#130)

Complete rewrite of the SDK documentation. The new doc/ structure includes a quick-start guide, getting-started guide, full SDK usage reference, Soroban guide, and 17 SEP protocol guides (SEP-01 through SEP-53). Every code snippet is validated by integration tests. The root README has been trimmed to a concise overview with a documentation table.

AI agent skill (#129)

Adds an Agent Skill that teaches AI coding agents how to build Stellar applications using the SDK. Compatible with any agent that supports the Agent Skills open standard (Claude Code, Codex CLI, Cursor, Gemini CLI, and others).

Auto-generated XDR types (#131)

The ~400 hand-written XDR type definitions have been replaced with machine-generated Dart code produced by a Ruby-based code generator that reads Stellar's canonical .x XDR definition files. This ensures correctness, adds 710 round-trip unit tests, and makes it easy to stay in sync with upstream XDR spec changes. The generator lives at tools/xdr-generator/ and a CI workflow ensures generated code stays in sync with the .x definitions.

Breaking changes:

• SorobanContractInfo.envInterfaceVersion replaced by envProtocolVersion and envPreReleaseVersion
• AssetTypePoolShare now requires named constructor parameters and uses toXdrChangeTrustAsset() instead of toXdr()
• Low-level XDR type changes — see the PR for details

Other

• Added compatibility matrix generators for Horizon, RPC, and SEP coverage tracking.