Improve WebSocket messages and reconnects

[scriptogre]

Why

Re-implement htmx 2.0's WebSocket extensions "queue messages during disconnected" behaviour. Reconnect only when a close is retryable, and give incoming and outgoing messages one hookable lifecycle.

Changes

<meta name="htmx-config"
      content='{"ws":{"reconnectCodes":[1006,1011,1012,1013]}}'>

Code 1000 stops by default. Per-element hx-config overrides global htmx.config.ws values.

Name events by direction

Before	After
htmx:before:ws:connection	htmx:ws:before:connection
htmx:after:ws:connection	htmx:ws:after:connection
htmx:before:ws:request	htmx:ws:before:message:outgoing
htmx:after:ws:request	htmx:ws:after:message:outgoing
htmx:before:ws:message	htmx:ws:before:message:incoming
htmx:after:ws:message	htmx:ws:after:message:incoming

Align with htmx:<extension>:<timing>:<noun>

Expose message-shaped hooks

Outgoing values move from a nested body to top-level keys. headers is reserved for htmx metadata.

// Before
{ "headers": { /* ... */ }, "body": { "message": "Hello" } }

// After
{ "headers": { /* ... */ }, "message": "Hello" }

Incoming hooks preserve native data and provide cached conversions:

event.detail = {
  message: { data, type, text(), json(), blob(), arrayBuffer() },
  waitUntil,
  cancelled
}

Docs

Docs now cover everything new, and Beta-to-RC1 migration.