wait: document value reference support in wait fields
Summary
Updates the wait step-type page to match the new behavior from dagucloud/dagu#3236 (closes dagucloud/dagu#3226): all wait fields now accept value references, deferring strict validation of reference-carrying values to run time.
Changes
step-types/wait.md: rewrote the Value References section — previously statedduration,until,url,state,status,poll_interval, andrequest_timeoutare validated as written and thatuntil: ${params.deadline}is rejected before the DAG runs; now documents that all fields accept references, references skip strict checks until they resolve at run time, and literals are still validated strictly at build time
Summary by cubic
Updates the wait step-type documentation to match the new behavior where all wait fields accept value references.
The Value References section previously claimed only path, method, headers, and body accept references, and that reference-carrying values like until: ${params.deadline} are rejected before the DAG runs. It now documents that references in any wait field skip strict validation until resolved at run time, while literal values are still validated strictly at build time. Also adds a YAML example showing a wait.until step using a parameter reference.