feat(dotfiles): rework awesomewm multi-monitor workflow

[TechDufus]

Summary

• improve AwesomeWM multi-monitor behavior with grouped window switching, screen-aware popups, and cross-screen window moves that preserve manual cell overrides
• add per-screen DPI-driven wibar sizing and geometry reflow for mixed-resolution monitor setups
• include the small accompanying config changes already on this branch: Codex service_tier = "fast" and the Ghostty background image swap

Validation

• ansible-playbook main.yml --syntax-check
• Lua loadfile() checks for touched AwesomeWM files
• live manual smoke testing on a mixed 4K + 1080p dual-monitor setup