v0.12.0

• Record the installing Whirl version in the shim bundle. An upgraded binary refuses a stale bundle with a runtime error naming whirl install, and whirl doctor reports the same, instead of running an older shim silently.
• Replace named inline HTTP actions with structured HTTP entries. Requests can run before VISIT, use multiline JSON or fenced text bodies, and assert or capture their response without a name. Whirl warns when an HTTP entry has no status assertion.