docs: add real-world examples page

[lonestarx1]

Summary

• Adds a new Real-World Examples docs page with 3 industry scenarios (healthcare, finance, infrastructure)
• Written for a non-technical audience (managers) — uses bullet-point breakdowns and business impact tables instead of code
• Adds "Examples" nav link to the docs layout

Test plan

• Verify page renders at /real-world-examples
• Verify nav link appears and works
• Review content for clarity