Fixes https://github.com/twentyhq/twenty/issues/18949
## Problem
- Creating a record from filters with DATE_TIME fields produced empty
objects instead of dates — `isPlainObject` from `twenty-shared` treats
`Date` instances as plain objects, so `mergeCompositeValues` spread them
into `{}`
- `buildRecordInputFromFilter` applied composite merge logic to all
field types indiscriminately, including primitives, dates, and strings
- DATE_TIME "is before" filters produced exact boundary values instead
of subtracting a minute
## Fix
- Composite and non-composite fields are now handled in separate
branches — `buildRecordInputFromFilter` uses `isCompositeFieldType` to
decide whether to merge or assign directly
- `mergeCompositeValues` extracted to its own file with a properly typed
signature (`Record<string, unknown>`) — no more runtime type guessing
- DATE_TIME fields with `IS_BEFORE` operand subtract one minute using
`subMinutes` from `date-fns`
- 13 unit tests for `mergeCompositeValues` covering all composite field
types (currency, address, full name, links, emails, phones) and
successive sub-field accumulation
