a4d6e7a348
Verifies that generate_mkcert() correctly passes Tailscale hostnames (spark-1.tail8f3c4e.ts.net, 100.64.0.1) through to the mkcert command arguments when extra_hostnames is provided. - fake_run tracks gen_calls only for '-cert-file' invocations - Creates fake cert/key files to simulate mkcert success - Asserts result is not None - Asserts Tailscale hostname appears in mkcert command args Part of Phase 2 full test sweep (task-7).