fix: resolve all TypeScript type errors across codebase for Deno strict mode

Comprehensive type safety improvements across all CLI handlers and daemon:

**Error handling type fixes:**
- Add 'error instanceof Error' checks before accessing error.message throughout
- Fix all error/retryError/stdError/upsError type assertions
- Replace direct error.message with proper type guards

**Switch case improvements:**
- Wrap case block declarations in braces to satisfy deno-lint
- Fix no-case-declarations warnings in CLI command handlers

**Null/undefined safety:**
- Add checks for config.snmp and config.thresholds before access
- Fix IUpsStatus lastStatusChange to handle undefined with default value
- Add proper null checks in legacy configuration paths

**Type annotations:**
- Add explicit type annotations to lambda parameters (groupId, updateAvailable, etc.)
- Add TUpsModel type cast for 'cyberpower' default
- Import and use INupstConfig type where needed

**Parameter type fixes:**
- Fix implicit 'any' type errors in array callbacks
- Add type annotations to filter/find/map parameters

Files modified:
- ts/cli.ts: config.snmp/thresholds null checks, unused error variable fixes
- ts/cli/group-handler.ts: 4 error.message fixes + 2 parameter type annotations
- ts/cli/service-handler.ts: 3 error.message fixes
- ts/cli/ups-handler.ts: 5 error.message fixes + config checks + TUpsModel import
- ts/daemon.ts: 8 error.message fixes + IUpsStatus lastStatusChange fix + updateAvailable type
- ts/nupst.ts: 1 error.message fix
- ts/systemd.ts: 5 error.message fixes + parameter type annotation

All tests passing (3/3 SNMP tests + 10/10 logger tests)
Type check: ✓ No errors

ts/cli/service-handler.ts

@@ -201,12 +201,12 @@ export class ServiceHandler {
         logger.logBoxEnd();
       } catch (error) {
         logger.logBoxLine('Error during update process:');
-        logger.logBoxLine(`${error.message}`);
+        logger.logBoxLine(`${error instanceof Error ? error.message : String(error)}`);
         logger.logBoxEnd();
         process.exit(1);
       }
     } catch (error) {
-      logger.error(`Update failed: ${error.message}`);
+      logger.error(`Update failed: ${error instanceof Error ? error.message : String(error)}`);
       process.exit(1);
     }
   }
@@ -300,7 +300,7 @@ export class ServiceHandler {
         stdio: 'inherit', // Show output in the terminal
       });
     } catch (error) {
-      console.error(`Uninstall failed: ${error.message}`);
+      console.error(`Uninstall failed: ${error instanceof Error ? error.message : String(error)}`);
       process.exit(1);
     }
   }