✨ Add oxlint-tsgolint for type-aware linting

Activates type-aware rules via oxlint --type-aware, backed by
oxlint-tsgolint (TypeScript-Go). Catches unsafe type assertions,
unnecessary type parameters, and other issues regular oxlint
cannot see.

- Add oxlint-tsgolint devDep + 6 platform-specific native bindings
  as optionalDependencies (same pattern as oxlint)
- Add --type-aware flag to check:oxlint
- Add 6 @oxlint-tsgolint/* platforms to check:outdated ignore list
- Disable 3 type-aware rules in .oxlintrc.json with rationale:
  - typescript/no-unsafe-type-assertion, typescript/no-unnecessary-type-parameters:
    fire on legitimate generic type machinery in keysMatch/MatchBuilder
    that needs type-system restructuring (deferred to a follow-up)
  - typescript/no-floating-promises in test files: expectTypeOf() is
    a sync type-assertion library that oxlint-tsgolint misidentifies

Code simplifications enabled by the new strict checks:
- src/match.ts: drop value as unknown casts (T is already assignable
  to unknown) and the redundant run(value) as R cast
- src/index.test.ts: drop unnecessary 'X' as 'X | Y' assertions in
  match<...>(...) calls (literals are already assignable to the union)

Documentation updates in project-specs.md and README.md. Add
'tsgolint' to cspell word list.

cspell.json

@@ -19,7 +19,8 @@
         "publint",
         "attw",
         "arethetypeswrong",
-        "knip"
+        "knip",
+        "tsgolint"
     ],
     "ignorePaths": ["dist", "node_modules", "coverage", "*.svg", ".gitignore"]
 }