docs: add X article source recovery fallback

[kleberAbreu]

Summary

• document public X status extraction for article cards
• record anonymous X Article login redirect behavior
• add a LinkedIn cross-post fallback for recovering author-controlled canonical URLs

Validation

• markdown reviewed locally
• git diff --check passed

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Summary by cubic

Add a docs page for recovering canonical article sources from public x.com/<handle>/status/<id> posts when X Article cards redirect to login. Includes public status link extraction, a LinkedIn cross-post fallback to resolve canonical URLs, and guardrails for safe citation.

^{Written for commit 62b1782. Summary will update on new commits.}

[cubic-dev-ai]

No issues found across 1 file

_{Re-trigger cubic}