feat(ai): Rename package to @mariozechner/pi-ai and improve documentation

- Changed package name from @mariozechner/ai to @mariozechner/pi-ai
- Fixed generate-models.ts to fetch from models.dev API instead of local file
- Completely rewrote README with practical examples:
  - Image input with base64 encoding
  - Proper tool calling with context management
  - Streaming with completion indicators
  - Abort signal usage
  - Provider-specific options (reasoning/thinking)
  - Custom model definitions for local/self-hosted LLMs
  - Environment variables explanation
- Bumped version to 0.5.9 and published

package-lock.json

@@ -2716,7 +2716,7 @@
 		},
 		"packages/agent": {
 			"name": "@mariozechner/pi-agent",
-			"version": "0.5.8",
+			"version": "0.5.9",
 			"license": "MIT",
 			"dependencies": {
 				"@mariozechner/pi-tui": "^0.5.8",
@@ -3098,7 +3098,7 @@
 		},
 		"packages/ai": {
 			"name": "@mariozechner/ai",
-			"version": "0.5.8",
+			"version": "0.5.9",
 			"license": "MIT",
 			"dependencies": {
 				"@anthropic-ai/sdk": "^0.60.0",
@@ -3134,7 +3134,7 @@
 		},
 		"packages/pods": {
 			"name": "@mariozechner/pi",
-			"version": "0.5.8",
+			"version": "0.5.9",
 			"license": "MIT",
 			"dependencies": {
 				"@mariozechner/pi-agent": "^0.5.8",
@@ -3150,7 +3150,7 @@
 		},
 		"packages/tui": {
 			"name": "@mariozechner/pi-tui",
-			"version": "0.5.8",
+			"version": "0.5.9",
 			"license": "MIT",
 			"dependencies": {
 				"@types/mime-types": "^2.1.4",