Cospend translations move to src/lib/i18n/cospend/{de,en}.ts with
satisfies-based key-set enforcement, mirroring the fitness layout
shipped earlier. cospendI18n.ts becomes the same kind of slim shim
exporting m, CospendLang, CospendKey while keeping every existing
helper (detectCospendLang, paymentCategoryName, splitDescription,
formatNextExecutionI18n, etc.) on the same surface.
Calendar gets the same treatment but with three locales (de/en/la)
and two namespaces — `ui` and the rite-1962-specific `ui1962`.
calendarI18n.ts now imports both as m / m1962, types them as
CalendarKey / Calendar1962Key, and routes t() / t1962() through
them. The 1962 fallback is per-namespace dir with file-prefixed
locale files (de_1962.ts etc.) so they can co-exist.
19 cospend route/component files and 3 calendar pages migrated to
the t.key / t1962.key syntax. Two notable hand fixes: UsersList.svelte
needed `as CospendLang` because the `lang` prop default uses an `as`
cast that breaks TS narrowing of m[lang]; and a sed pass converted
codemod-emitted t['camelCase'] to t.camelCase since the static-key
regex initially only matched snake_case.
The split + codemod scripts are now generic — split-i18n.ts takes
namespace, locales, optional marker and basename for multi-table
modules; codemod-i18n-t-to-m.ts takes module basename, fn name, and
m alias name (so t1962 / m1962 share the same machinery as t / m).
The fitness-specific one-shots are deleted, superseded.
