Support form-driven frame navigation

[brophdawg11]

This extends frame-aware navigation to eligible same-origin forms while preserving native form behavior before the client runtime loads. Applications continue to own request construction in resolveFrame; the runtime only forwards the browser's submission metadata.

• Changes resolveFrame(src, signal, target) to resolveFrame(src, options) with formData, method, encType, signal, and target.
• Preserves native constraint validation, submitter overrides, progressive enhancement, and explicit document-navigation escape hatches.
• Uses replace history for same-location non-GET submissions while preserving push history for different destinations and GET submissions.
• Demonstrates GET course filtering and POST account editing through the frame-navigation demo's new /account/edit route.
• Stacked on Support redirects from frame reloads #11667 and supersedes the form-submission portion of Support form-driven frame navigation #11632.

<form method="post" action="/account/edit" rmx-target="account">
  <label for="display-name">Display name</label>
  <input id="display-name" name="displayName" required />
  <button type="submit">Save</button>
</form>

run({
  async resolveFrame(src, options) {
    return fetch(src, {
      method: options?.method,
      body: options?.method?.toLowerCase() === 'post' ? options.formData : undefined,
      signal: options?.signal,
    })
  },
})

[github-actions]

Preview Build Available

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pnpm install "remix-run/remix#preview/pr-11668&path:packages/remix"

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