Add dynamic upload limits based on server boost level with catbox.moe fallback

[Claude]

Implements dynamic file size limits for video downloads based on Discord server boost level, with automatic fallback to catbox.moe for oversized files.

Changes

• Dynamic upload limits: File size limits now scale with server boost level (Level 1: 10MB, Level 2: 50MB, Level 3: 100MB, Non-boosted: 25MB)
• Catbox.moe fallback: Files exceeding Discord limits but under 200MB are automatically uploaded to catbox.moe and shared as links
• Configurable failure handling: Emoji reactions (default: 💥) for files exceeding catbox.moe's 200MB limit
• New commands:
  • /videodl setcatbox <userhash> - Configure catbox.moe authentication
  • /videodl setemoji <emoji> - Customize the too-large file reaction
• Enhanced status: /videodl status now shows boost level, current file size limit, and catbox configuration

Example

# Automatic handling based on file size:
# 1. ≤ boost limit → Upload directly to Discord
# 2. > boost limit but ≤ 200MB → Upload to catbox.moe, post link
# 3. > 200MB or catbox fails → React with configured emoji

Dependencies: Added catboxpy>=0.0.5 to support external hosting.

[psykzz]

@copilot fix tests

[Copilot]

@copilot fix tests

Fixed in 81746c3. The two failing tests needed os.path.getsize mocked (since on_message now checks file size after download), and MockGuild needed a premium_tier attribute to support the new boost-level size limit logic.