Adds label support to contact import and export so teams can carry
approved contact labels through CSV workflows. Imports accept a `labels`
column with labels that already exist in the account; multiple labels
should be entered as a quoted comma-separated CSV value, for example
`"customer,vip"`.
Imports are additive: they add labels to contacts and do not remove
labels already on a contact. Removing a label from the CSV row or
leaving the `labels` cell blank will not clear existing contact labels.
To remove a label, edit the contact directly.
## Closes
- Closes#8535
## How to test
1. Create a few contact labels in the account, such as `customer`,
`vip`, and `lead`.
2. Go to Contacts -> Import contacts and download the sample CSV.
3. Import contacts with a `labels` column. Use a single label like
`lead`, or quote multiple labels like `"customer,vip"`.
4. Confirm imported contacts are created with the expected labels.
5. Re-import an existing contact with a new label and confirm the new
label is added without removing existing labels.
6. Try a row with an unknown label, such as `"vip,unknown_label"`, and
confirm only that row is rejected in the failed records CSV while the
other valid rows are imported.
7. Export contacts and confirm the CSV includes a `labels` column with
comma-separated approved labels.
## What changed
- Contact exports include approved `labels` in the default CSV columns.
This adds a new default export column for CSV consumers.
- Contact imports parse `labels` as comma-separated values inside the
CSV cell.
- Imported labels are validated against labels that already exist in the
account.
- Rows with unknown labels are rejected with an `Unknown labels: ...`
error; valid rows in the same import continue to process.
- Imported labels are additive and do not remove existing contact
labels.
- Label application during import does not dispatch an additional
per-contact update event.
- The sample CSV includes an import-safe `labels` column. The modal
keeps the existing generic CSV import copy.
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Co-authored-by: Sojan Jose <sojan@pepalo.com>
