Remove legacy pc tables, fix ASP issues, update dashboard APIs

Database changes (run sql/migration_drop_pc_tables.sql on prod):
- Drop pc, pc_backup_phase2, pc_to_machine_id_mapping tables
- Rename pcid columns to machineid in machineoverrides, dualpathassignments, networkinterfaces
- Recreate 9 views to use machines.machineid instead of pcid
- Clean orphaned records and add FK constraints to machines table

ASP fixes:
- editprinter.asp: Fix CLng type mismatch when no printerid provided
- includes/sql.asp: Remove AutoDeactivateExpiredNotifications (endtime handles expiry)
- includes/leftsidebar.asp: Update fiscal week banner styling, remove dead Information link
- charts/warrantychart.asp: Use vw_warranty_status instead of pc table

Dashboard API renames (naming convention):
- shopfloor-dashboard: Update to use apishopfloor.asp, apibusinessunits.asp
- tv-dashboard: Rename api_slides.asp to apislides.asp

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

sql/drop_legacy_pc_tables.sql

@@ -0,0 +1,23 @@
+-- ============================================================================
+-- Drop Legacy PC Tables
+--
+-- These tables are no longer used after PC migration to machines table.
+-- All ASP code now uses machines table or vw_warranty_status view.
+--
+-- Run this AFTER verifying the application works correctly.
+-- ============================================================================
+
+-- Verify no dependencies before dropping
+-- SELECT * FROM information_schema.KEY_COLUMN_USAGE
+-- WHERE REFERENCED_TABLE_NAME IN ('pc', 'pc_backup_phase2');
+
+-- Drop the legacy tables
+DROP TABLE IF EXISTS pc_backup_phase2;
+DROP TABLE IF EXISTS pc;
+
+-- Verify tables are gone
+SHOW TABLES LIKE 'pc%';
+
+-- Expected remaining tables:
+--   pc_to_machine_id_mapping  (still needed by views)
+--   pctype                    (still needed for PC type lookups)