nodejs/cli-extension: resolving sdk paths and error log should be improved

[ilsubyeega]

1. Doing like this will result error: Error: Cannot find package '@github/copilot-sdk' imported from ...

import { joinSession } from "@github/copilot-sdk/extension.js";

instead of..

import { joinSession } from "@github/copilot-sdk/extension";

(.js difference)

2. Error handling should be more improved, at CLI v1.0.12, it shows only single line not stacktrace etc, so hard to debug. e.g:

[INFO] Launching extension: /tmp/copilot/test/.github/extensions/test/extension.mjs
[INFO] [extension:/tmp/copilot/test/.github/extensions/test/extension.mjs] [extension-bootstrap] Failed to load extension: SyntaxError: Unexpected token 'export'
[INFO] Extension exited: /tmp/copilot/test/.github/extensions/test/extension.mjs (code=1, signal=null)
[ERROR] Extension failed during startup: /tmp/copilot/test/.github/extensions/test/extension.mjs (code=1, signal=null)

[INFO] Found 1 extension(s), launching 1 (0 disabled)
[INFO] Launching extension: /tmp/copilot/test/.github/extensions/test/extension.mjs
[INFO] [extension:/tmp/copilot/test/.github/extensions/test/extension.mjs] [extension-bootstrap] Failed to load extension: Error: Invalid package config /tmp/copilot/test/.github/extensions/test/package.json.
[INFO] Extension exited: /tmp/copilot/test/.github/extensions/test/extension.mjs (code=1, signal=null)
[ERROR] Extension failed during startup: /tmp/copilot/test/.github/extensions/test/extension.mjs (code=1, signal=null)

[ilsubyeega]

Also importing local file would fail due to no package.json, only log are shown following:

The requested module './src/hooks/index.js' does not provide an export named 'createHook'

creating ./src/package.json with content {} fixed it though(not sure about root level atm)

edit: it did work on ./package.json too.

[ilsubyeega]

more things:

• createHook configuration type is somehow looks like not to be completed list (or not all handled correctly)? some property like customAgents are passed thru but never read, which kinda interesting that there has a api of registering command/hooks/perm-handler/tools/userhandler/transformer etc but not like subagent.
• CustomAgentConfig isn't complete type yet? model property do not exist here, probably worth to add reasoning levels into there too.