fix: harden comment-aware hover and folding

[tzzs]

Summary

• normalize method hover doc comments for triple-slash comments so rendered text does not keep an extra leading slash
• support hash comments as hover documentation and avoid treating inline block comments on previous code lines as docs for the next method
• make folding range bracket and parenthesis scans reuse the core tokenizer comment masking so line comments, hash comments, and block comments do not create fake list/map/parameter folds
• export ThriftTokenizer from thrift-core so VS Code providers can share the same comment and token handling instead of hand-rolling it

Verification

• npm run lint:fix
• npm run lint
• npm run build
• npm test (1164 passing)