Auto-Expire or Report Option for AMP Cached Pages from 404 Origin URLs

### Description

Currently, AMP cached pages on `cdn.ampproject.org` continue to appear in Google SERPs even when the origin page is completely inaccessible (i.e., returns a 404 Not Found or 410 Gone). This causes major abuse potential, especially in cases involving:

* Hacked domains (e.g., .gov or .edu sites)
* Blackhat SEO using AMP for parasite hosting
* Expired or abandoned domains serving stale AMP content

The AMP cache still serves the page **even after the source is long gone** — creating the illusion of valid content and polluting search results.

🚀 Feature Request:

1. **Auto-refresh or invalidate AMP cache** when the origin consistently returns 404/410 on fetch.
2. **Add a “Report this AMP page” button** on the AMP cache viewer page (e.g., `https://xxx.cdn.ampproject.org/c/s/domain.com/path`) for pages whose origin no longer exists.
3. Include a mechanism to revalidate stale cache from a source that no longer meets the serving criteria (expired cert, 404 origin, etc).

### Alternatives Considered

* Manually reporting AMP cache pages via Google Search “Feedback” system (not scalable, inconsistent results, and lacks visibility).
* Waiting for AMP cache expiration passively, which may take weeks or months — often **long after the origin has disappeared**.
* Using the “Remove Outdated Content” tool from Google Search Console, which requires user-side manual effort and is not always reliable for mass abuse cases.

### Additional Context

#### 🕵️ Example of Abuse Case:

* **AMP Cache URL:**
`https://kasih--profit-pages-dev.cdn.ampproject.org/c/s/kasih-profit.pages.dev/judi%20slot%20microstar88/`
* **Original Source:**
`https://ppdb.man2kotabjm.sch.id/resources/?hkm=judi%20slot%20microstar88`
→ This returns **404** (confirmed).

These stale AMP cache entries are being widely exploited for blackhat SEO manipulation, especially via hacked government and educational websites. This undermines both the credibility of AMP as a technology and Google's index integrity.

A feature like automatic invalidation or a user-accessible report button would help significantly mitigate this abuse.