chore: remove .team dir and fix golangci-lint issues

[stenh0use]

Two housekeeping changes bundled together.

Remove .team directory

Deletes the .team folder which is no longer needed.

Fix golangci-lint issues and add v2 config

Resolves all 14 findings and adds a .golangci.yml to make linting explicit and repeatable.

• rm_test.go — replace os.Setenv with t.Setenv (auto-restores, checked error)
• locks_test.go — delete unused snapshot() method
• locks_test.go, status_snapshot_service_test.go — //nolint:staticcheck on intentional nil context tests
• start.go — lowercase error string per Go conventions
• repository.go — check f.Close() error in syncPath without defer
• .golangci.yml — v2 config enabling errcheck/staticcheck/unused; suppresses errcheck for fmt.F* stream writes (fire-and-forget is idiomatic in CLI output)