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/redis.toml

@@ -0,0 +1,28 @@
+id = "redis"
+name = "Redis"
+description = "Access and manage Redis key-value stores through the MCP server"
+category = "data"
+icon = "🔴"
+tags = ["database", "cache", "key-value", "in-memory", "nosql"]
+
+[transport]
+type = "stdio"
+command = "npx"
+args = ["-y", "@modelcontextprotocol/server-redis"]
+
+[[required_env]]
+name = "REDIS_URL"
+label = "Redis Connection URL"
+help = "A Redis connection URL (e.g., redis://user:password@host:6379/0)"
+is_secret = true
+get_url = ""
+
+[health_check]
+interval_secs = 60
+unhealthy_threshold = 3
+
+setup_instructions = """
+1. Obtain your Redis connection URL from your Redis hosting provider or local instance (e.g., redis://localhost:6379/0).
+2. If authentication is required, include the password in the URL: redis://user:password@host:6379/0.
+3. Paste the full connection URL into the REDIS_URL field above.
+"""