refactor(claude): consolidate and rename skills

- Merge git and github skills into single git/SKILL.md with SmartEM context
- Add project board ID and labels reference to git skill
- Delete ascii-art skill (not essential for cryo-EM development)
- Rename database-admin -> database
- Rename technical-writer -> tech-writer
- Rename playwright-skill -> playwright
- Update claude-code-config.json with new skill names/paths

Closes #116

Author: vredchenko

claude-code/shared/skills/ascii-art/SKILL.md

@@ -1,11 +1,11 @@
 ---
-name: Database Admin
+name: Database
 description: PostgreSQL administration, Alembic migrations, schema design, and database troubleshooting for smartem-decisions
 version: 1.0.0
 tags: [database, postgresql, alembic, migrations, schema]
 ---
 
-# Database Admin Skill
+# Database Skill
 
 PostgreSQL database administration and Alembic migration management for the SmartEM system.