Establish Twitcher for Redot

[dominicbytes]

What changed

• makes Twitcher for Redot the project and addon identity
• targets and tests Redot 26.2 LTS
• adapts the editor setup API for Redot
• replaces Godot-facing installation, editor, HTTP, and OAuth labels with Redot equivalents
• adds Redot compatibility CI and an isolated runtime probe

Relationship to the original

This is an independent Redot project derived from kani_dev's original Twitcher: https://github.com/kanimaru/twitcher

It retains attribution, the MIT license, and compatible public API paths, but is maintained separately and is not intended to merge back into the original repository.

Validation

• Redot 26.2 stable (4f5b14aba)
• 433 scripts import without parse or load failures
• compatibility probe loads the plugin and setup scenes and instantiates TwitchService
• GitHub Actions runs the pinned Redot 26.2 compatibility check

Live Twitch OAuth, API, and EventSub behavior requires credentials and is outside the automated probe.