docs: strengthen comparison page intro, Best fit, and OWASP threading

[sonukapoor]

The comparison page has three structural weaknesses that reduce its effectiveness for user adoption and positioning:

1. Opening paragraph undersells the tool — leads with 'not trying to be everything for everyone' instead of a clear value statement
2. Best fit section is generic — five vague bullets without a strong positioning close
3. OWASP recognition is inconsistent — only mentioned mid-page in Snyk/Socket sections, not in the intro or closing

This issue tracks a focused pass to fix all three structural gaps without touching the individual tool comparison sections.