Catalog text lives in translation files

Amends ADR 0008.

Exercise names, instructions, variation notes and aliases move out of catalog/data/exercises.json into the catalog namespace of the translation files (ADR 0014), keyed by slug: goblet-squat.name, goblet-squat.instructions.0, goblet-squat.variationNote, goblet-squat.aliases. Aliases are one comma-separated message per language, since a message is a single string; they are never shown. exercises.json keeps the structure: slug, movement pattern, muscles, equipment, measurement, variations, retired and version.

The text moves so translators can edit it in Fink alongside the rest of the app. What the phone receives does not change shape: the build merges the text back into the bundled catalog, so each catalog version stays one self-contained document, copied into the database and later published by the server as ADR 0008 says, with each text as a map from language to string ({"en": "Goblet squat", "fr": "Squat gobelet"}). That is the JSON phones already store, so existing catalog entries decode unchanged and no migration is needed.

Consequences

• Changing an exercise's text raises the catalog version, as any catalog change does. Fink's pull requests don't, so CI fails when catalog text changes and version doesn't, and the version is raised before merging.
• A slug is also a message id prefix, one more reason it never changes.
• Reordering an exercise's instructions renumbers their ids, and translators see the change as new messages.
• The build fails when an exercise has no name in a shipped language, or a message names a slug the catalog lacks.