feat(managed-qa): add value comparison and FAQ

[malinosqui]

What changed

• Adds a static “math vs. building QA in-house” comparison after Managed QA pricing.
• Expands the FAQ with commercial and procurement questions: inclusions, kickoff timeline, monthly billing, required access, scope expansion, and release-SLA expectations.
• Keeps the comparison above the decorative bug layer so its numbers remain readable.

Why

The page now makes the build-vs-buy trade-off explicit and answers the questions that typically block a buyer from booking a fit call.

Validation

• Checked the staged diff for whitespace errors.
• Verified the comparison and expanded FAQ in the local preview, including the responsive layout rules.
• Confirmed the US salary anchor is conservative against current BLS QA/tester median-pay data; the page labels the figures as US-market estimates.