fix(db): regenerate ChatSettings migration for semanticSearchEnabled (v19)

[jung-thomas]

Problem

DEV deploy fails at HDI make building AdminService.ChatSettings.hdbview:

Database error 260: invalid column name CHATSETTINGS_0.SEMANTICSEARCHENABLED

Root cause

PR #2246 (feat(search): public anonymous semantic_search) added semanticSearchEnabled : Boolean to db/schema.cds and advanced db/last-dev/csn.json (commit fc464b8), but never regenerated the ChatSettings hdbmigrationtable. The model and last-dev both carried the column while the migration table stayed at version=18, so the generated .hdbview referenced a column the table never added.

This is the 3rd occurrence of the same miss (v16 puzzleHint dbb41e2, v17 alerts 5abf73a).

Fix

Regenerated the migration table via cds build --production (compiler 7.0.1, matching CI), adding:

== migration=19
ALTER TABLE com_sap_developers_ims_ChatSettings ADD (semanticSearchEnabled BOOLEAN DEFAULT FALSE);

Single-file change. last-dev/csn.json already carries the column from #2246, so the migration table is the only missing piece — a canonical two-task cds build --production reproduces this table byte-identically with last-dev unchanged (verified locally with the DEV-pinned cds 10.1.0).

Test

• Canonical cds build --production produces exactly this diff, no further migrations, last-dev clean.
• Unblocks the DEV MTA deploy (will re-run once merged).