feat: add classification-based filtering and fix company name display

- Added classification column to companies table
- Created excluded_classifications setting (default: Tools Only)
- Updated kiosk stats and activity APIs to filter by classification
- Added comprehensive classification filtering UI with checkboxes
- Support for common classifications (Tools Only, Wulff Consulting Client, Customer)
- Allow custom classification entry
- Fixed company name display in settings (convert string IDs properly)
- Classification filtering works alongside company ID exclusions

migrations/020_add_company_classification.sql

@@ -0,0 +1,14 @@
+-- Add classification column to companies table
+-- This will store the classification name (e.g., "Tools Only", "Wulff Consulting Client", "Customer")
+ALTER TABLE companies ADD COLUMN IF NOT EXISTS classification VARCHAR(255);
+
+-- Create index for faster filtering
+CREATE INDEX IF NOT EXISTS idx_companies_classification ON companies(classification);
+
+-- Add classification to kiosk settings
+INSERT INTO kiosk_settings (setting_key, setting_value, description) VALUES
+  ('excluded_classifications', 'Tools Only', 'Comma-separated list of company classifications to exclude from kiosk')
+ON CONFLICT (setting_key) DO NOTHING;
+
+-- Add comment
+COMMENT ON COLUMN companies.classification IS 'Company classification (e.g., Tools Only, Wulff Consulting Client, Customer)';