Enhance /temporale endpoint with object wrapper and i18n support

[JohnRDOrazio]

Summary

The /temporale endpoint currently returns raw JSON arrays and doesn't support i18n data management in PUT/PATCH requests.

Problems

1. Security concern: GET/POST responses return raw JSON arrays, which can be vulnerable to JSON hijacking in older browsers
2. Inconsistent with /data endpoint: PUT/PATCH don't handle i18n data, unlike the /data endpoint pattern
3. No protection against accidental overwrites: PUT can overwrite existing data without warning

Proposed Solution

1. Object wrapper for responses

Wrap GET/POST responses in an object:

{
  "events": [...],
  "locale": "en"
}

2. i18n support in PUT/PATCH

Accept i18n data in request payloads:

{
  "events": [...],
  "locales": ["en", "la", "de"],
  "i18n": {
    "en": { "Easter": "Easter Sunday", ... }
  }
}

3. PUT creation-only behavior

• PUT should only work when NO temporale data exists (initial creation)
• Return 409 Conflict if data already exists
• Use PATCH for updates

4. i18n consistency

• Every event_key must exist in ALL i18n files
• Use empty string as placeholder for untranslated entries
• Require Accept-Language locale translations for new event_keys

Breaking Changes

This is a breaking change for:

• Clients expecting array response from GET/POST
• Clients sending array payload to PUT/PATCH
• PUT behavior (now fails if data exists)

Since the endpoint is new and not yet in production, this is acceptable.