Replace the compile-time cfg!(target_os = "macos") jamo-width heuristic
with a runtime override (process-global AtomicU8 in pi-natives, mirrored in
the TS width engine) plus terminal-identity detection: Ghostty renders
Hangul Compatibility Jamo (U+3131..U+318E) at 2 cells, so it is forced wide;
every other terminal keeps the platform default (macOS narrow, otherwise
UAX#11), making the override a no-op outside Ghostty.
Fixes doubled/ghosted jamo during Korean IME composition on Ghostty, where
the hardware cursor landed inside the typed text and the IME candidate window
drifted from the glyph. The width is resolved synchronously before the first
paint, so no stdin/CPR probe or async cache invalidation is needed.
A runtime DSR/CPR probe that auto-detects the width on unknown terminals is
tracked in a follow-up.
- Removed configurable tab width support and the `display.tabWidth` setting across all packages.
- Deleted obsolete utility functions `getIndentation`, `getIndentationNoescape`, and `setDefaultTabWidth`.
- Standardized tab expansion logic to use a fixed `DEFAULT_TAB_WIDTH` globally.
- Cleaned up related configuration schemas, test suites, and internal API signatures to remove path-dependency.
- Fixed `visibleWidth` parity with native width using `Bun.stringWidth` ANSI stripping.
- Fixed tab and OSC66 width parsing with `s=`/`w=` metadata handling.
- Added ASCII and long-string fast paths in `visibleWidth` for faster width checks.
- Consolidated visible-width regression coverage by replacing removed IME/Arabic/Jamo tests with `visible-width.test.ts`.
changhee.an