Add industry file: Healthcare / MedTech

[glacierphonk]

Task

Add a healthcare naming guide at `industries/healthcare.md`. Depends on #180.

Why healthcare naming is distinct

• Regulatory naming — FDA, EMA, and other regulators have rules about what health products can imply in their names
• Clinical vs consumer — clinical tools (Epic, Cerner) have different naming than consumer health apps (Calm, Headspace)
• Trust is non-negotiable — patients trust these products with health data and medical decisions
• "Wellness" vs "medical" — naming signals which side of the line the product sits on. Regulatory implications differ
• Latinized medical vocabulary — medical terminology provides a naming source that signals expertise (but can alienate patients)

Sections to cover

• Regulatory constraints per jurisdiction
• Case studies: Epic, Cerner, Calm, Headspace, Hims, Ro, One Medical
• Anti-patterns: pseudo-clinical names, "Health" prefix fatigue, overpromising in the name
• Territory map: Restoration/healing, vitality/pulse, care/nurture, precision/clinical

Before submitting

Read CONTRIBUTING.md and run `markdownlint-cli2 '**/*.md'` before pushing.