rename: libcosmic → libcosmic-yoda (fork 0.1.0-yoda)

Fork point: pop-os/libcosmic 1.0.0 + perf/quickwins-bundle + macOS
window controls feature. From here the crate diverges under the yoda
lineage with its own versioning.

Changes:
- Cargo.toml: name = libcosmic-yoda, version = 0.1.0-yoda
- [lib] name = cosmic kept unchanged — consumer code still does 'use cosmic::...'
- examples/*/Cargo.toml: updated all libcosmic dep references to libcosmic-yoda
- i18n/*/libcosmic.ftl renamed to libcosmic_yoda.ftl (71 locales) to match
  the new name expected by fluent_language_loader!() macro

cargo check --lib passes. Examples not yet validated — Phase 2 (Wayland-only
cut) will rework them anyway.

i18n/bg/libcosmic.ftl

@@ -1,29 +0,0 @@
-# Context Drawer
-close = Затваряне
-# About
-license = Лиценз
-links = Връзки
-developers = Разработчици
-designers = Дизайнери
-artists = Художници
-translators = Преводачи
-documenters = Документатори
-january = Януари { $year }
-february = Февруари { $year }
-march = Март { $year }
-april = Април { $year }
-may = Май { $year }
-june = Юни { $year }
-july = Юли { $year }
-august = Август { $year }
-september = Септември { $year }
-october = Октомври { $year }
-november = Ноември { $year }
-december = Декември { $year }
-monday = Пн
-tuesday = Вт
-wednesday = Ср
-thursday = Чт
-friday = Пт
-saturday = Сб
-sunday = Нд