refactor: rename custom provider examples

- custom-provider -> custom-provider-anthropic
- gitlab-duo -> custom-provider-gitlab-duo
- Update READMEs with custom provider section

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

@@ -88,6 +88,13 @@ cp permission-gate.ts ~/.pi/agent/extensions/
 |-----------|-------------|
 | `mac-system-theme.ts` | Syncs pi theme with macOS dark/light mode |
 
+### Custom Providers
+
+| Extension | Description |
+|-----------|-------------|
+| `custom-provider-anthropic/` | Custom Anthropic provider with OAuth support and custom streaming implementation |
+| `custom-provider-gitlab-duo/` | GitLab Duo provider using pi-ai's built-in Anthropic/OpenAI streaming via proxy |
+
 ### External Dependencies
 
 | Extension | Description |

packages/coding-agent/examples/extensions/custom-provider-anthropic/package.json

@@ -1,5 +1,5 @@
 {
-  "name": "pi-extension-custom-provider",
+  "name": "pi-extension-custom-provider-anthropic",
   "private": true,
   "version": "1.0.0",
   "type": "module",

packages/coding-agent/examples/extensions/custom-provider-gitlab-duo/package.json

@@ -1,5 +1,5 @@
 {
-  "name": "pi-extension-gitlab-duo",
+  "name": "pi-extension-custom-provider-gitlab-duo",
   "private": true,
   "version": "1.0.0",
   "type": "module",