- Rename all user-facing and technical identifiers from OpenPets/Pet to FamiliarOS/Familiar.
- Rename packages from @open-pets/* to @familiaros/*; rename install-pet/pet-format packages.
- Rename plugin IDs and directories from openpets.* to familiaros.*.
- Rename IPC namespace from openpets:* to familiaros:* and state filenames from openpets-* to familiaros-* with legacy migration.
- Rename source files (pet-window, built-in-pet, default-pet-controller, etc.) to familiar equivalents.
- Update locales (en, es-419, ja, ko, pt-BR, zh-Hans, zh-Hant) and tray/pet context menu strings.
- Add Familiar naming feature: preference, settings input, tray menu display.
- Update assets and packaging config; all desktop tests pass.
