Migrate commands from bash scripts and VSCode tasks to package.json scripts

[kmturley]

Features:

• Migrate bash scripts to package scripts
• Update VSCode tasks to use package scripts
• Use ssh key instead of password.
• Deploy ssh commands combined to improve deployment time.

Only tested on Steam Deck directly. Needs testing remotely from a Linux device -> Steam Deck.

Commands could be cleaned up further e.g. to remove echo statements etc, but left in to try and keep functionality as close as possible to current.

One thing to note is that pnpm run build is a "reserved" command as it is run inside Docker during decky cli command. Therefore I had to namespace pnpm run build:plugin to prevent a build loop.

[kmturley]

Running time pnpm run build:deploy locally on the Steam Deck it takes only 7 seconds! This is with Docker images are already downloaded and layers cached. We can benchmark against current build/deploy task but definitely feel faster.

I think there are additional optimizations if the frontend could build directly to /home/deck/homebrew/plugins/plugin-name/dist then you could almost get to live-reload (except for the refresh button in DeckyLoader). I think I will try that in a separate PR, as live reload might require some other changes to the dev commands vs build commands.

[kmturley]

As a reference SteamBrew is doing the same for tasks.json:
https://github.com/SteamClientHomebrew/PluginTemplate/blob/main/.vscode/tasks.json

But the package.json commands are encapsulated in the command line tool:
https://github.com/SteamClientHomebrew/PluginTemplate/blob/main/package.json#L4