Per-element cross-check between phx-value-* attributes and the declared params on the corresponding action.

Composes with ValidateEvents: that transformer ensures every literal event name resolves to some declared action. This one ensures that on any element with phx-click="name" (or phx-submit/phx-change/etc.), the set of phx-value-foo attribute keys exactly matches the declared args: list for action :name.

Rules:

• Each phx-value-foo key on the element must appear in the action's declared args. Unknown keys ⇒ DslError (typo detection).
• Each declared arg must appear as a phx-value-foo key. Missing args ⇒ DslError.
• Dynamic event names (phx-click={@x}) are skipped — the binding to a specific action isn't resolvable at compile time.
• Dynamic phx-value-foo={@x} values are fine; only the key is checked, not the value's runtime type.
• Event names that don't match any declared action are not reported here — ValidateEvents already raises in that case. We just skip them to avoid double-reporting.