Merge pull request #8 from oshokin/feat/k6-v2-support

feat: add k6 v2 support and simplify E2E tooling

fix: reject directory targets in ReplaceFile on Windows

Windows remove+rename could replace an empty directory path with an export
temp file, making export finalize succeed where Unix failed. Validate targets
before replacement so export cleanup/failure behavior stays consistent.

fix: align community lint workflow and task recipes

Make compliance checks reproducible by wiring Taskfile vulncheck/xk6-lint-community to the go.mod toolchain and documenting all task recipes in README. This also removes whitespace autofix conflicts and adds explicit nosec rationale so gosec and xk6 community lint pass consistently.

fix: scope extension-check workflow token to read-only

Declare workflow-level `permissions: contents: read` so the default
GITHUB_TOKEN is not granted write access this CI job does not need.

Extension Check only checks out the repo, runs linters/tests, and
reports results; it never pushes commits, opens releases, or mutates
repository settings. Least-privilege permissions match that surface
and align with org/repo policies that restrict default workflow
token scopes.

fix: E2E key/prefix/metric fixes, many-keys []string, JSONL paths, Se…

…rializedStore split

fix: release action

fix: build auto-tagged releases in the same workflow

fix: include TypeScript lockfile for CI caching

fix: add randomKeys() for prefix-scoped batch key sampling with disk/…

…memory backends, metrics, and tests

fix: document KV metrics observability and align examples with covere…

…d APIs