fix: align TypeScript SDK exports, client options, and internal methods with Python parity and F-08 specifications

feat: add Rust implementation and update SDKs for apcore 0.15.1 compatibility

docs: update v0.3.0 CHANGELOG and README for cross-language sync

docs: remove `apcore-toolkit` dependency bump entry from CHANGELOG.

docs: rename JWT_SECRET env var to APCORE_JWT_SECRET

feat: Add SkillMapper display overlay for skill ID, description, and tags, and remove the unused `_build_extensions()` method and its documentation.

chore: rebrand aipartnerup → aiperceivable

docs: update README with a new tagline, expanded metadata details, and A2A mapping for skill tags and metadata.

docs: Enhance README with official SDK links and multi-language examples, and reorganize documentation specifications into a dedicated `spec/` folder.

feat: Migrate server core to a2a-sdk components, expand public API exports, and update documentation for Python 3.11+ and apcore 0.9.0+.

feat: Replace the main logo with a jellyfish design and move the previous clownfish logo to a new image file.

docs: Update getting started guide to use language-specific tabs for code examples.

feat: Establish MkDocs documentation site with GitHub Pages deployment and initial changelog.

feat: Add comprehensive getting started and features documentation, and update README to include TypeScript installation details.

feat: Add apcore-a2a logo and display it in the README.