Bounce feedback to the prefilled Google form instead of posting it

[enf0rc3]

Back-pocket alternative to #3393. Keeps the sidebar UI and stops the page submitting anything at all.

Send stops being a form post and becomes an <a> to the form's own viewform URL, with the fields prefilled. The reader presses submit on Google's side, so nothing on our page can be made to submit — which is what protected us before #3324, since scanners scope to the target domain and don't follow off-site links.

What it does

• Send is a link, not a button. Its href carries usp=pp_url plus the page, the rating and the comment, rebuilt as the reader votes and types.
• It works without our script. Astro renders the link at build time with the page title already prefilled, exactly as the pre-Move feedback into the right side-nav  #3324 button did. The script only enriches it.
• It opens in its own tab. setExternalLinkAttributes() already adds target="_blank" and rel="noopener" to any off-site link, so the reader keeps their place in the docs. That's better than the old button, which navigated away.
• The thanks message is gone. We can't know whether someone submitted on Google's side, so claiming it would be a lie.
• Label changed from "Send" to "Send feedback", since a button that opens a form elsewhere shouldn't say "Send".
• A comment over 1500 characters is cut, because a prefill travels in the URL. The reader sees the cut text in the form and can finish it there.

Verified against the live form

I loaded a prefilled URL in a browser and checked all three fields land (viewing only, nothing submitted):

Field	Prefilled
Which page did you view?	Deploy with Kustomize - https://octopus.com/docs/kubernetes/steps/kustomize
How useful was the content?	5 selected on the 1–5 scale
Please tell us what we did well…	the comment text

npx playwright test tests/feedback.spec.ts — 8 passing, including one that asserts no request reaches docs.google.com however the widget is worked.

Worth knowing before choosing between this and #3393

Both models require a comment. The form marks "Please tell us what we did well, or what we could improve" as required. So under this PR a reader who clicks a thumb still has to type something on Google's page before their rating counts. That is almost certainly what kept the old flow's volume low, and it means the two approaches converge for the reader: no comment, no feedback.

If we want vote-only feedback in either model, the form field has to be made optional first. That's a Forms settings change, not a code one.

The remaining cost here is friction. Every response now needs a page load on another domain and a second click to submit. #3393 keeps the submission inline and pays for it with a filter that is targeted at the scanner's current behaviour.

Draft on purpose — this is the fallback if the required-comment approach in #3393 stops working, or if we decide we want the structural guarantee now rather than later.

🤖 Generated with Claude Code

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