test: batch 19 — theming, automations, range-highlight edge cases (55 tests) (#438)
Theming (20 tests): unique IDs, valid base types, builtIn flag, named themes,
case-sensitive lookup, CSS var value matching, multi-override custom themes,
base inheritance, empty string resolve, deleteCustomTheme edge cases.
Automations (24 tests): unique rule IDs, multiple actions, maxExecutions
defaults, row filter, combined column+row filter, row_added/deleted triggers,
non-numeric value_greater/less_than, case-insensitive value_contains,
null/undefined value_is_empty, numeric coercion in value_equals, unknown
trigger type, empty state, multiple matching rules, unlimited executions,
recordExecution isolation, duplicate preserves trigger/actions/enabled state.
Range-highlight (11 tests): empty formula, numbers-only formula, mixed
absolute/relative refs, cross-sheet ranges, multi-letter columns, complex
nested formulas, TRUE/FALSE exclusion, all 6 palette colors, palette source
verification, duplicate ref color sharing.
Total tests: 6,638