Update extension for latest Roc LSP

[lukewilliamboswell]

Summary

• update the extension API dependency and wasm target validation for current Zed extension builds
• launch Roc with experimental-lsp --stdio
• add Roc outline captures for nominal type declarations, type-module methods, and var declarations
• add just check and more robust grammar query sync/update recipes
• remove the unused legacy src/roc.rs stub and refresh docs/CI

[lukewilliamboswell]

Local QA update:

• Dev extension install/rebuild now succeeds in Zed after aligning the local grammars/roc checkout URL with [grammars.roc].repository in extension.toml.
• just sync-queries and just check pass locally.
• Roc LSP smoke testing with the sibling Roc patch returns document symbols for type-only modules.

The PR remains draft pending final review.