Update alacritty, yabai, and add test-anthropic-key script

[drewjs]

Summary

• Add Shift+Return keybinding to Alacritty that sends escape sequence (\e\r)
• Add Screen Studio and Screen Studio Beta to yabai unmanaged app rules
• Add test-anthropic-key utility script to bin

🤖 Generated with Claude Code

[claude]

PR Review - Overall clean and focused changes. A few notes below.

alacritty.toml Shift+Return binding: (1) Minor placement - the new [[keyboard.bindings]] entry is after [general] while all other bindings are at the top. TOML is fine with this but grouping them together would be more consistent. (2) Minor casing - existing bindings use \u001B uppercase for ESC, new one uses \u001b lowercase. Functionally identical.

yabai/.yabairc Screen Studio rules: Looks good. Unanchored pattern is consistent with existing Raycast and CleanShot entries.

bin/.local/bin/test-anthropic-key: (1) Concern - hardcoded model claude-sonnet-4-5-20250929 may be deprecated over time, causing failures with a valid key. A cheaper stable model like claude-haiku-4-5-20251001 would be more resilient. (2) Minor - key passed as argument is visible in ps aux; env var is safer, worth highlighting in usage text. (3) Minor - no curl exit code check means network failures surface as a misleading Key failed message rather than a network error.

Overall solid - the script is a useful utility, just worth hardening the model ID and curl error handling.