feat: add agent skills and guardrails functionality

- Introduced new tools for managing agent skills and guardrails, including add, remove, and list operations.
- Updated README.md to document new commands and usage patterns for skills and guardrails.
- Enhanced server configuration to support longer read and write timeouts.
- Increased maximum upload size for files to 100 MB and adjusted related configurations.
- Created database migrations for agent skills, guardrails, and their associations with projects.
- Updated relevant code files to integrate new skills and guardrails into the application logic.

configs/config.example.yaml

@@ -1,8 +1,8 @@
 server:
   host: "0.0.0.0"
   port: 8080
-  read_timeout: "15s"
-  write_timeout: "30s"
+  read_timeout: "10m"
+  write_timeout: "10m"
   idle_timeout: "60s"
   allowed_origins:
     - "*"