feat(build): configure project tooling and update dependencies

- Replace placeholder deps with click, pygnmi, and rich for CLI functionality
- Add fabric-orch CLI entry point via project.scripts
- Configure hatchling as build backend with wheel/sdist targets
- Add ruff linter configuration for code quality
- Add dev dependency group with ruff
- Alphabetize yang module imports

src/gnmi/__init__.py

@@ -0,0 +1,23 @@
+"""
+gNMI Client Module for Fabric Orchestrator.
+
+This module provides a gNMI client wrapper for interacting with
+Arista devices using pygnmi.
+
+Usage:
+    from gnmi import GNMIClient
+
+    async with GNMIClient(
+        host="leaf1",
+        port=6030,
+        username="admin",
+        password="admin",
+        insecure=True
+    ) as client:
+        caps = await client.capabilities()
+        print(caps)
+"""
+
+from src.gnmi.client import GNMIClient, GNMIConnectionError, GNMIError, GNMIPathError
+
+__all__ = ["GNMIClient", "GNMIError", "GNMIConnectionError", "GNMIPathError"]