* docs: add ANTLR grammar review and improvement suggestions

- Added detailed documentation in `ANTLR-grammar-review_codex.md`, `grammar_review_gemini.md`, and `PARSER_IMPROVEMENTS_CC.md` outlining enhancements for readability, maintainability, and performance
- Includes lexer and parser recommendations, refactoring suggestions, and transition strategies
- Structured with concrete examples and incremental implementation guidance for ease of adoption

* refactor: update and optimize whitespace handling in sequenceLexer

- Introduced `HWS` fragment for horizontal whitespace, reused across rules.
- Adjusted `COMMENT` rule to handle line breaks consistently.
- Updated `DIVIDER` to use `HWS` for improved maintainability.

* fix: resolve inconsistent newline handling in comments parsing and tests

- Updated test cases to reflect consistent newline formatting across comment assertions.
- Adjusted `Comment` and `parser/index.js` to handle and normalize newline characters.
- Removed Bun-specific script from `package.json` for `dev` command.
- Regenerated `sequenceLexer` to accommodate modifications.

* refactor(parser): improve string handling and rule consistency

- Replaced `STRING` with `CSTRING` and `USTRING` for better closed/unclosed string differentiation.
- Consolidated repetitive `ID | STRING` patterns into a reusable `name` rule.
- Simplified `parExpr` with optional sequence rules to reduce complexity.
- Removed parser-side logging in `stat` for cleaner error-handling practices.
- Updated and regenerated lexer/parser outputs to reflect changes.

* left-factor messageBody; introduce fromTo

* Simplified group to reduce alternatives while preserving tolerance.

* Simplified loop while keeping editor tolerance.

* fix: update import path and fix typo in Store.ts