chore: replace Biome with oxlint, oxfmt and Knip

[Thomasims]

Moves the repository onto the shared @antelopejs/tooling-configs presets: oxlint with the vendored anti-slop rules, oxfmt for formatting, and Knip for dead code.

Tooling

biome.json and @biomejs/biome are gone, replaced by oxlint.config.ts, oxfmt.config.ts and knip.config.ts. lint, lint:fix and format point at the new tools, and format:check and knip are new.

tsconfig

Type-aware linting runs through tsgolint, which rejects options TypeScript 7 removes and auto-discovers each file's own tsconfig.json, so both the root and the playground config change. moduleResolution: "node" (node10) is removed in TS7 and goes; baseUrl gives way to an explicit rootDir. module deliberately stays on commonjs: under node16 TypeScript stops downlevelling await import(...) and emits a native ESM dynamic import, which does not go through the AntelopeJS CJS resolver detour. Leaving module alone and simply dropping moduleResolution satisfies tsgolint and keeps the emit byte-compatible, so type-aware linting is fully enabled.

Code changes the linter asked for

Nothing beyond the import ordering that oxlint --fix applies. The two remaining findings are anti-slop warnings (no-unknown-type-aliases on AuthPayload, no-object-parameters on jwt.ts) which the preset raises deliberately and which do not fail the build. They are backlog items, not a gate.

Knip

mocha was declared as a runtime dependency and nothing imports it — the mocha the suites run under comes from the test runner, not from this package. Removing it leaves pnpm test at 4 passing, so it goes.

chai, @types/chai and @types/mocha look equally unused from the source but are not removable: the auth conformance suite ships compiled inside @antelopejs/interface-auth and require("chai") out of this module's own node_modules. They are recorded in ignoreDependencies with that reason. ajs is ignored because CI installs @antelopejs/core globally rather than pulling the whole CLI into the dependency tree.

Verification

pnpm build, pnpm lint and pnpm knip are clean. pnpm test is 4 passing / 0 failing — identical to untouched main, measured in a throwaway worktree before any of this landed.

The formatting pass is its own commit and is recorded in .git-blame-ignore-revs.

The .github/ISSUE_TEMPLATE/** entry in oxfmt.config.ts is temporary and can be dropped once AntelopeJS/tooling-configs#5 ships.