feat(automations): implement model eligibility checks for automation creation

- Added model eligibility checks to ensure automations can only use billable models (premium or BYOK).
- Introduced new API endpoint to report model eligibility status for search spaces.
- Updated frontend components to display eligibility alerts and disable creation options when models are not billable.
- Enhanced automation creation forms to reflect model eligibility, preventing users from submitting invalid configurations.
- Implemented server-side logic to capture and preserve model preferences across automation edits, ensuring consistent behavior during execution.

surfsense_web/lib/query-client/cache-keys.ts

@@ -134,5 +134,7 @@ export const cacheKeys = {
 			["automations", "runs", automationId, limit, offset] as const,
 		run: (automationId: number, runId: number) =>
 			["automations", "runs", automationId, runId] as const,
+		modelEligibility: (searchSpaceId: number) =>
+			["automations", "model-eligibility", searchSpaceId] as const,
 	},
 };