feat(ai): add @oh-my-pi/pi-ai package with tool name prefixing

- Port pi-ai from upstream with Bun-first approach (source files, no dist)
- Add cli_ prefix to tool names in OAuth mode to avoid collisions
- Improve beta header handling with proper deduplication
- Convert codex-instructions.md to Bun text embed
- Strip .js extensions from all imports

packages/coding-agent/examples/extensions/README.md

@@ -113,7 +113,7 @@ export default function (pi: ExtensionAPI) {
 **Use StringEnum for string parameters** (required for Google API compatibility):
 
 ```typescript
-import { StringEnum } from "@mariozechner/pi-ai";
+import { StringEnum } from "@oh-my-pi/pi-ai";
 
 // Good
 action: StringEnum(["list", "add"] as const);

packages/coding-agent/examples/extensions/todo.ts

@@ -10,7 +10,7 @@
  * correct for that point in history.
  */
 
-import { StringEnum } from "@mariozechner/pi-ai";
+import { StringEnum } from "@oh-my-pi/pi-ai";
 import type { ExtensionAPI, ExtensionContext, Theme } from "@oh-my-pi/pi-coding-agent";
 import { matchesKey, Text, truncateToWidth } from "@oh-my-pi/pi-tui";
 import { Type } from "@sinclair/typebox";
@@ -263,7 +263,7 @@ export default function (pi: ExtensionAPI) {
 					return new Text(
 						`${theme.fg("success", "✓ Added ") + theme.fg("accent", `#${added.id}`)} ${theme.fg("muted", added.text)}`,
 						0,
-						0,
+						0
 					);
 				}