♻️ Move type-aware config to .oxlintrc.json; use source-level disable directives

Cleaner separation of concerns:
- options.typeAware: true in .oxlintrc.json activates type-aware
  rules declaratively (equivalent to --type-aware CLI flag, but
  the script command stays clean: just 'oxlint ...')
- Remove the 3 type-aware rule disables from .oxlintrc.json
- Add source-level oxlint-disable directives instead:
  - 4x typescript/no-unsafe-type-assertion (pattern.ts: keysMatch
    Object.keys() cast, candidate[] cast; structuralMatcher value
    as S cast; match.ts: handler as ... cast in nextCases)
  - 1x typescript/no-unnecessary-type-parameters (pattern.ts:
    keysMatch <S extends object>)
  - 1x file-level typescript/no-floating-promises in index.test.ts
    (expectTypeOf() is a sync type-assertion library that the
    type-aware linter misidentifies)

Disabling rules at the source (next to the line that needs the
exemption) documents intent more clearly than a global config
override, and makes the trade-off visible to anyone reading the
code. Re-enabling a rule in the future only requires removing the
inline comment, not editing a central config.

project-specs.md

@@ -21,11 +21,14 @@ typescript-lib-starter-tiny => https://github.com/tmueller/typescript-lib-starte
 - **oxlint**: Rust-based linter. Replaces ESLint. Config in `.oxlintrc.json`
   with `typescript`, `unicorn`, `oxc`, `import` plugins. Categories enabled
   as errors: `correctness`, `suspicious`, `restriction`. As warnings: `perf`,
-  `style`. `nursery` is off. Run with `--type-aware` to enable rules
-  that require TypeScript type information (powered by `oxlint-tsgolint`).
+  `style`. `nursery` is off. Type-aware rules are enabled via
+  `options.typeAware: true` in `.oxlintrc.json` (no CLI flag needed);
+  the linter then uses `oxlint-tsgolint` for rules that require type
+  information.
 - **oxlint-tsgolint**: TypeScript-Go-backed type-aware linter for oxlint.
-  Activated via `oxlint --type-aware`. Native bindings installed as
-  `optionalDependencies` per platform (same pattern as oxlint).
+  Activated by `options.typeAware: true` in `.oxlintrc.json`. Native
+  bindings installed as `optionalDependencies` per platform (same
+  pattern as oxlint).
 - **oxlint rules disabled by design** (in `.oxlintrc.json`):
     - `eslint/no-undefined` — we use `undefined` as the no-match sentinel.
     - `eslint/sort-keys` — handler/case order is semantic, not alphabetical.
@@ -222,22 +225,25 @@ script does not belong in the standard pipeline.
 
 - `check`: Run all checks in order — `check:oxlint`, `check:oxfmt`,
   `check:tsc`, `check:cspell`, `check:knip`, `check:outdated`.
-- `check:oxlint`: `oxlint --type-aware ${LEFTHOOK_FILES:-src}` — lints
-  `src/` by default; when invoked from the lefthook pre-commit hook
-  with `LEFTHOOK_FILES` set to the staged-files list, lints only those
-  files. The `--type-aware` flag enables type-aware rules via
-  `oxlint-tsgolint` (TypeScript-Go-backed). This is the single source
-  of truth for the oxlint command and is shared between the manual
-  `npm run check` and the pre-commit hook. oxlint only understands
-  JS/TS-family languages, so config files (JSON/YAML/Markdown) are
+- `check:oxlint`: `oxlint ${LEFTHOOK_FILES:-src}` — lints `src/` by
+  default; when invoked from the lefthook pre-commit hook with
+  `LEFTHOOK_FILES` set to the staged-files list, lints only those
+  files. This is the single source of truth for the oxlint command
+  and is shared between the manual `npm run check` and the pre-commit
+  hook. Type-aware rules are activated declaratively via
+  `options.typeAware: true` in `.oxlintrc.json` (not via a CLI flag),
+  so the script command stays clean. oxlint only understands JS/TS-
+  family languages, so config files (JSON/YAML/Markdown) are
   intentionally outside its scope; they are checked only by oxfmt.
-  Type-aware rules disabled (with rationale in `.oxlintrc.json`):
-  `no-unsafe-type-assertion` and `no-unnecessary-type-parameters`
-  fire on legitimate generic type machinery in `keysMatch` /
-  `MatchBuilder` that needs type-system restructuring (out of scope
-  for the tool-adoption commit); `no-floating-promises` is disabled
-  in test files because `expectTypeOf(...)` is a sync type assertion
-  library that oxlint-tsgolint misidentifies.
+  Source-level `oxlint-disable` directives are used to silence
+  type-aware false positives in the generic type machinery: 4× for
+  `typescript/no-unsafe-type-assertion` and 1× for
+  `typescript/no-unnecessary-type-parameters` in `src/pattern.ts` /
+  `src/match.ts` (legitimate type machinery that needs restructuring,
+  documented in the source); 1× file-level for
+  `typescript/no-floating-promises` in `src/index.test.ts`
+  (`expectTypeOf(...)` is a sync type-assertion library that
+  oxlint-tsgolint misidentifies).
 - `check:oxfmt`: `oxfmt --check ${LEFTHOOK_FILES:-.}` — formats the
   whole project (`.`) by default, including JS/TS, JSON/JSONC,
   YAML, Markdown, MDX and other supported file types. From lefthook