fix: rename environment variables to match MCP server expectations

Gitea MCP server expects:
- GITEA_API_URL (not GITEA_URL) - must include /api/v1
- GITEA_API_TOKEN (not GITEA_TOKEN)

NetBox MCP server expects:
- NETBOX_API_URL (not NETBOX_URL) - must include /api
- NETBOX_API_TOKEN (not NETBOX_TOKEN)

Changes:
- Update all setup commands to use correct variable names
- Update docs/CONFIGURATION.md with correct variables and URL format
- Update scripts/setup.sh templates
- Update CLAUDE.md hybrid configuration reference
- Remove GITEA_ORG from system-level config (it's project-level)
- Fix API URL paths in curl commands (remove redundant /api/v1)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

CLAUDE.md

@@ -140,7 +140,7 @@ leo-claude-mktplace/
 
 | Level | Location | Purpose |
 |-------|----------|---------|
-| System | `~/.config/claude/gitea.env` | Credentials (GITEA_URL, GITEA_TOKEN) |
+| System | `~/.config/claude/gitea.env` | Credentials (GITEA_API_URL, GITEA_API_TOKEN) |
 | Project | `.env` in project root | Repository specification (GITEA_ORG, GITEA_REPO) |
 
 **Note:** `GITEA_ORG` is at project level since different projects may belong to different organizations.