yoda: re-apply hard rename — libcosmic → libcosmic-yoda (0.1.0-yoda)

Reverts the soft-fork pivot (6736a596). Strategy chosen with user:
full cascade fork. Every consumer (leyoda/cosmic-files + each leyoda/app)
depends on libcosmic-yoda by explicit path, so there are no transitive
deps left asking for the upstream 'libcosmic' crate — no [patch]
unification issues, no two-version traps.

Changes:
- Cargo.toml: name = libcosmic-yoda, version = 0.1.0-yoda
- i18n/*/libcosmic.ftl -> libcosmic_yoda.ftl (71 locales)
- examples/*/Cargo.toml dep refs back to libcosmic-yoda
- compat stub features (winit=[], x11=[]) kept for upstream deps that
  might still request them during the migration window

cargo check --lib passes.

i18n/is/libcosmic_yoda.ftl

@@ -0,0 +1,8 @@
+close = Loka
+license = Notandaleyfi
+links = Tenglar
+developers = Forritarar
+designers = Hönnuðir
+artists = Listafólk
+translators = Þýðendur
+documenters = Skjölunarhöfundar