Update tree-sitter grammar for modern Roc syntax

[lukewilliamboswell]

Summary

• update tree-sitter-roc to the modern Roc syntax grammar from Support modern Roc syntax faldor20/tree-sitter-roc#43
• sync the generated Zed highlight query and validate its capture names
• improve Zed-specific brackets, indentation, outline, and text-object queries
• remove string injections that captured delimiters instead of string content
• avoid quote auto-closing inside comments

Validation

• cargo fmt -- --check
• cargo clippy --all-targets -- -D warnings
• cargo test
• cargo build --target wasm32-wasip2
• all Zed query files compile against the updated grammar
• scripts/check-highlight-captures.sh
• manual QA against current Roc sources and examples

Dependency

Depends on faldor20/tree-sitter-roc#43. The manifest currently pins its published head commit (fc80e44f452314518550d947bcfdde6c3001a405) and should be updated if that branch is rebased before merge.