ReactiveUIToolKit

Add support for a new Unity version to ReactiveUIToolKit. Run when a new Unity release is available (user says "add Unity 6.5 support", "new Unity version came out", etc.). Discovers API changes via the automation~ diff scripts, classifies them, and implements support across all layers (PropsApplier/Style/StyleKeys/CssHelpers, schema, LSP, docs site) plus record-keeping.

The centralized IDE-extension changelog system. Use when adding a changelog entry, bumping extension versions, releasing, or editing any of ide-extensions~/changelog.json, scripts/changelog.mjs, the per-IDE CHANGELOG.md, vscode/README.md, or UitkxVsix/overview.md. Covers the add/extract/extract-overview/verify commands, the generated-marketplace-pages rule (edit templates, never outputs), and the Windows argv mojibake pitfalls.

Style and hard constraints for Plans~/DISCORD_CHANGELOG.md entries (the Discord release-notes posts). Use whenever adding or editing an entry there — hard 2000-char-per-entry cap, ASCII-only, prepend-only.

Rebuild the VS Code and/or Visual Studio 2022 extensions locally for F5 / Extension-Development-Host testing. Use when the user says "rebuild for F5", "rebuild the extension", "build the LSP server locally", "test the extension change" or after editing files under `ide-extensions~/language-lib/`, `ide-extensions~/lsp-server/`, `ide-extensions~/vscode/`, `ide-extensions~/visual-studio/`, or `Editor/HMR/`. Covers the full local pipeline — language-lib build, LSP server emit, TS client bundle, VSIX server-binary copy — and the artifact-size verification step. Does NOT cover Marketplace releases — those are handled by `.github/workflows/publish.yml`.