docs: expand npm audit comparison with concrete examples and structured sections

[sonukapoor]

The CVE Lite CLI vs npm audit section is thin compared to the Dependabot section — just an intro sentence and 4 generic bullets. It needs to be expanded to give developers a real, concrete understanding of how the two tools differ.

Changes

Expand the ## CVE Lite CLI vs npm audit section in website/docs/comparison.md to match the depth of the Dependabot section, covering:

• Why finding counts differ — npm audit counts each node in a transitive dependency chain as a separate finding; CVE Lite groups by root cause
• Fix suggestion quality — npm audit suggests --force with an unvalidated version; CVE Lite validates the fix and gives an exact copy-and-run command
• Output noise — npm audit lists all individual CVEs per package flat; CVE Lite groups them
• npm-only limitation — npm audit doesn't work with pnpm or Yarn lockfiles
• Where npm audit has the edge — honest acknowledgement: built-in, no install required

Grounded in real output from the examples/direct-fixable and examples/transitive-path-high example repos.