chore: Mark AI package implementation task as complete

- Moved completed AI package implementation task to done folder
- Task successfully implemented the unified AI API (@mariozechner/pi-ai)
- Package renamed, documentation improved, and published as v0.5.12

packages/agent/package-lock.json

@@ -1,12 +1,12 @@
 {
 	"name": "@mariozechner/pi-agent",
-	"version": "0.5.11",
+	"version": "0.5.12",
 	"lockfileVersion": 3,
 	"requires": true,
 	"packages": {
 		"": {
 			"name": "@mariozechner/pi-agent",
-			"version": "0.5.11",
+			"version": "0.5.12",
 			"license": "MIT",
 			"dependencies": {
 				"@mariozechner/tui": "^0.1.1",