vapor_split: report events and v-model as bindings (0.16.0) - #6

For vize 0.16.0. This takes LiveView's conventions out of vapor_split, so vize_ex stays a binding to Vize and PhoenixVapor owns how events are rendered.

Before

vapor_split wrote LiveView attributes into the statics:

Vize.vapor_split!(~s(<button @click="save">{{ label }}</button>)).statics
# ["<button phx-click=\"save\">", "</button>"]

v-model also added phx-change="<name>_changed", a naming convention of PhoenixVapor's. Callers couldn't opt out: PhoenixVapor's hybrid mode, where Vue in the browser handles events, still got phx-click attributes, which LiveView acts on until the client mounts.

After

Events and v-models are left unrendered and returned as bindings:

{:ok, split} = Vize.vapor_split(~s(<button @click="save">{{ label }}</button>))

split.statics   # ["<button>", "</button>"]
split.bindings  # [%{kind: :set_event, node: %{key: {:static_, "click"}, value: "save", ...}, at: {0, 7}}]

• node is the Vapor IR node, encoded exactly as vapor_ir/1 does: a SetEventIRNode, with its modifiers, or the v-model DirectiveIRNode.
• at is {static_index, byte_offset}: where the element's start tag ends, so the caller can insert attributes there without parsing HTML.
• Every nested v-if and v-for split carries its own :bindings.

Binding markers go through the same marker pass as slots, so positions are exact even when slots come before them in the same tag or static.

Breaking

vapor_split's output changes, so this is 0.16.0. PhoenixVapor is the only known consumer, and its adaptation is ready on a branch.

Volt 0.19 requires vize ~> 0.15.0. A Volt release accepting 0.16 is needed before PhoenixVapor, which requires Volt, can move to it.

Verification

VIZE_EX_BUILD=1 mix ci passes: lint (including rustq.gen --check, clippy and Dialyzer) and 122 tests. New tests cover:

• event bindings with modifiers;
• v-model bindings;
• positions in a later static;
• bindings inside v-if and v-for blocks.

rustq.gen --check also passes under MIX_ENV=test.