fix: align switch-exhaustiveness-check with upstream

[fansenze]

Summary

• Align @typescript-eslint/switch-exhaustiveness-check diagnostics and missing-case order with TypeScript/typescript-eslint behavior.
• Generate enum and unique-symbol suggestions only from checker-proven runtime paths, preserving aliases, namespace qualification, renamed exports, type-only boundaries, and compiler-target-aware property access.
• Match defaultCaseCommentPattern with ECMAScript Unicode (u) semantics and ECMAScript whitespace trimming, with bounded compilation, matching, caching, and file-local resource fuses.
• Fully escape generated JavaScript string literals and document intentional process-safety and suggestion-safety differences.
• Keep default-comment lookup and edit construction demand-aware so ordinary diagnostics avoid optional work.

Go benchmark

Median of 8 runs:

GOWORK=off go test ./internal/plugins/typescript/rules/switch_exhaustiveness_check \
  -run '^$' \
  -bench '^BenchmarkSwitchExhaustivenessCheck$' \
  -benchmem \
  -benchtime=100ms \
  -count=8

Case	ns/op before → after	B/op before → after	allocs/op before → after
Exhaustive matched	2507.5 → 2132.5	4854 → 3197.5	65 → 44
Missing diagnostics only	6314 → 5819.5	16919.5 → 15234.5	180 → 159
Missing suggestion	15905 → 6603	77342.5 → 17792.5	357 → 175
Non-union default diagnostics	1793 → 1433	5268 → 3675	57 → 44
Non-union default suggestion	1944 → 1635	5637 → 4044	63 → 50
Custom pattern matched	3159 → 5938	9616 → 13783	100 → 291
Custom pattern no-match	3827 → 6757.5	10765 → 16213	112 → 319
Unnecessary default	1578.5 → 1587.5	3340 → 3340	42 → 42
No-switch control	1107 → 1087.5	3131 → 3131	36 → 36

The custom-pattern cases reflect the deliberate cost of replacing regexp2's approximation with an ECMAScript-compatible engine; default and ordinary diagnostic/suggestion paths improve or remain allocation-neutral.

Related Links

• typescript-eslint rule documentation
• typescript-eslint v8.67.0 implementation

Checklist

• Tests updated (or not required).
• Documentation updated (or not required).