Add healthcare/ division: Clinical Evidence Agent and Sovereign Health Systems Agent (#655)

Agents developed by Snark Health (github.com/snark-health).

Snark Health was founded by a practicing US physician with 25 years
of internal medicine and infectious disease experience and direct
leadership of a $2 billion risk-based Medicare bundled payment
contract with the US government, and a Kenyan engineer and operator
whose collaboration with the founding physician began in 1998 in
rural western Kenya. The frameworks in these files come from a team
that has delivered care in both US hospital systems and
resource-limited settings, managed actuarial risk under government
contract, and built health infrastructure across two continents
over 25 years.

AI Collective OS: snarkhealth.ai
Agent registry: snarkhealth.ai/registry

.github/workflows/lint-agents.yml

@@ -9,6 +9,7 @@ on:
       - "finance/**"
       - "game-development/**"
       - "gis/**"
+      - "healthcare/**"
       - "marketing/**"
       - "paid-media/**"
       - "sales/**"
@@ -33,7 +34,7 @@ jobs:
         id: changed
         run: |
           FILES=$(git diff --name-only --diff-filter=ACMR origin/${{ github.base_ref }}...HEAD -- \
-            'academic/**/*.md' 'design/**/*.md' 'engineering/**/*.md' 'finance/**/*.md' 'game-development/**/*.md' 'gis/**/*.md' 'marketing/**/*.md' 'paid-media/**/*.md' 'sales/**/*.md' 'security/**/*.md' 'product/**/*.md' \
+            'academic/**/*.md' 'design/**/*.md' 'engineering/**/*.md' 'finance/**/*.md' 'game-development/**/*.md' 'gis/**/*.md' 'healthcare/**/*.md' 'marketing/**/*.md' 'paid-media/**/*.md' 'sales/**/*.md' 'security/**/*.md' 'product/**/*.md' \
             'project-management/**/*.md' 'testing/**/*.md' 'support/**/*.md' \
             'spatial-computing/**/*.md' 'specialized/**/*.md')
           {