Add Antigravity manager CLI and dashboard tab

refactor: extract common shell logic into shared library cp-lib.sh

fix: improve model selection, account toggle, and auto-restart functionality

refactor: complete menu redesign with consistent styling

fix: resolve custom provider removal flow and dashboard modal issues

feat: add account toggle, interactive model selection for OpenCode/Droid, and refactor dashboard

Initial commit v2.0.0 Release

Initial Commit: v1.0.0 Release