refactor: replace 'any' types with proper TypeScript interfaces

Major type safety improvements throughout the codebase:

- Updated DEFAULT_CONFIG version to 4.2
- Replaced 'any' with proper types in systemd.ts:
  * displaySingleUpsStatus now uses IUpsConfig and NupstSnmp types
  * Fixed legacy config handling to use proper IUpsConfig format
  * Removed inline 'any' type annotations

- Replaced 'any' with proper types in daemon.ts:
  * emergencyUps now properly typed as { ups: IUpsConfig, status: ISnmpUpsStatus }
  * Exported IUpsStatus interface for reuse
  * Added ISnmpUpsStatus import to disambiguate from daemon's IUpsStatus

- Replaced 'any' with Record<string, unknown> in migration system:
  * Updated BaseMigration abstract class signatures
  * Updated MigrationRunner.run() signature
  * Updated migration-v4.0-to-v4.1.ts to use proper types
  * Migrations use Record<string, unknown> because they deal with
    unknown config schemas that are being upgraded

Benefits:
- TypeScript now catches type errors at compile time
- Would have caught the ups.thresholds bug earlier
- Better IDE autocomplete and type checking
- More maintainable and self-documenting code

ts/migrations/base-migration.ts

@@ -28,18 +28,18 @@ export abstract class BaseMigration {
   /**
    * Check if this migration should run on the given config
    *
-   * @param config - Raw configuration object to check
+   * @param config - Raw configuration object to check (unknown schema for migrations)
    * @returns True if migration should run, false otherwise
    */
-  abstract shouldRun(config: any): Promise<boolean>;
+  abstract shouldRun(config: Record<string, unknown>): Promise<boolean>;
 
   /**
    * Perform the migration on the given config
    *
-   * @param config - Raw configuration object to migrate
+   * @param config - Raw configuration object to migrate (unknown schema for migrations)
    * @returns Migrated configuration object
    */
-  abstract migrate(config: any): Promise<any>;
+  abstract migrate(config: Record<string, unknown>): Promise<Record<string, unknown>>;
 
   /**
    * Get human-readable name for this migration

ts/migrations/migration-runner.ts

@@ -32,7 +32,9 @@ export class MigrationRunner {
    * @param config - Raw configuration object to migrate
    * @returns Migrated configuration and whether migrations ran
    */
-  async run(config: any): Promise<{ config: any; migrated: boolean }> {
+  async run(
+    config: Record<string, unknown>,
+  ): Promise<{ config: Record<string, unknown>; migrated: boolean }> {
     let currentConfig = config;
     let anyMigrationsRan = false;
 

ts/migrations/migration-v4.0-to-v4.1.ts

@@ -49,15 +49,15 @@ export class MigrationV4_0ToV4_1 extends BaseMigration {
   readonly fromVersion = '4.0';
   readonly toVersion = '4.1';
 
-  async shouldRun(config: any): Promise<boolean> {
+  async shouldRun(config: Record<string, unknown>): Promise<boolean> {
     // Run if config is version 4.0
     if (config.version === '4.0') {
       return true;
     }
 
     // Also run if config has upsDevices with thresholds at UPS level (v4.0 format)
-    if (config.upsDevices && config.upsDevices.length > 0) {
-      const firstDevice = config.upsDevices[0];
+    if (Array.isArray(config.upsDevices) && config.upsDevices.length > 0) {
+      const firstDevice = config.upsDevices[0] as Record<string, unknown>;
       // v4.0 has thresholds at UPS level, v4.1 has them in actions
       return firstDevice.thresholds !== undefined;
     }
@@ -65,14 +65,15 @@ export class MigrationV4_0ToV4_1 extends BaseMigration {
     return false;
   }
 
-  async migrate(config: any): Promise<any> {
+  async migrate(config: Record<string, unknown>): Promise<Record<string, unknown>> {
     logger.info(`${this.getName()}: Migrating v4.0 config to v4.1 format...`);
     logger.dim(`  - Moving thresholds from UPS level to action level`);
     logger.dim(`  - Creating default shutdown actions from existing thresholds`);
 
     // Migrate UPS devices
-    const migratedDevices = (config.upsDevices || []).map((device: any) => {
-      const migrated: any = {
+    const devices = (config.upsDevices as Array<Record<string, unknown>>) || [];
+    const migratedDevices = devices.map((device) => {
+      const migrated: Record<string, unknown> = {
         id: device.id,
         name: device.name,
         snmp: device.snmp,
@@ -80,20 +81,21 @@ export class MigrationV4_0ToV4_1 extends BaseMigration {
       };
 
       // If device has thresholds at UPS level, convert to shutdown action
-      if (device.thresholds) {
+      const deviceThresholds = device.thresholds as { battery: number; runtime: number } | undefined;
+      if (deviceThresholds) {
         migrated.actions = [
           {
             type: 'shutdown',
             thresholds: {
-              battery: device.thresholds.battery,
-              runtime: device.thresholds.runtime,
+              battery: deviceThresholds.battery,
+              runtime: deviceThresholds.runtime,
             },
             triggerMode: 'onlyThresholds', // Preserve old behavior (only on threshold violation)
             shutdownDelay: 5, // Default delay
           },
         ];
         logger.dim(
-          `    → ${device.name}: Created shutdown action (battery: ${device.thresholds.battery}%, runtime: ${device.thresholds.runtime}min)`,
+          `    → ${device.name}: Created shutdown action (battery: ${deviceThresholds.battery}%, runtime: ${deviceThresholds.runtime}min)`,
         );
       } else {
         // No thresholds, just add empty actions array
@@ -104,7 +106,8 @@ export class MigrationV4_0ToV4_1 extends BaseMigration {
     });
 
     // Add actions to groups
-    const migratedGroups = (config.groups || []).map((group: any) => ({
+    const groups = (config.groups as Array<Record<string, unknown>>) || [];
+    const migratedGroups = groups.map((group) => ({
       ...group,
       actions: group.actions || [],
     }));