feat: sync content definitions from core repo

Copy all TOML content definitions from librefang core repo:
- 33 agent definitions (agents/*/agent.toml)
- 14 hand definitions with docs (hands/*/HAND.toml + SKILL.md)
- 25 integration templates (integrations/*.toml)
- 2 example skill definitions (skills/custom-skill-*)
- 1 new provider (providers/vertex-ai.toml)

Part of the framework-vs-content registry split (RFC v0.7).

integrations/gitlab.toml

@@ -0,0 +1,28 @@
+id = "gitlab"
+name = "GitLab"
+description = "Access GitLab projects, merge requests, issues, and CI/CD pipelines through the MCP server"
+category = "devtools"
+icon = "🦊"
+tags = ["git", "vcs", "code", "merge-requests", "ci", "devops"]
+
+[transport]
+type = "stdio"
+command = "npx"
+args = ["-y", "@modelcontextprotocol/server-gitlab"]
+
+[[required_env]]
+name = "GITLAB_PERSONAL_ACCESS_TOKEN"
+label = "GitLab Personal Access Token"
+help = "A personal access token with api scope from your GitLab instance"
+is_secret = true
+get_url = "https://gitlab.com/-/user_settings/personal_access_tokens"
+
+[health_check]
+interval_secs = 60
+unhealthy_threshold = 3
+
+setup_instructions = """
+1. Navigate to GitLab > User Settings > Access Tokens (https://gitlab.com/-/user_settings/personal_access_tokens).
+2. Create a new personal access token with the 'api' scope and an appropriate expiration date.
+3. Paste the token into the GITLAB_PERSONAL_ACCESS_TOKEN field above.
+"""