chore: remove zod package and replace with TypeScript types

[Claude]

Removes the zod runtime validation library and replaces it with native TypeScript interfaces for type safety. The action generates all metrics data internally, making runtime validation unnecessary overhead.

Changes

• Type definitions (src/lib.ts): Replaced zod schemas with TypeScript interfaces:

  • cpuLoadPercentageSchema → CpuLoadPercentage interface
  • memoryUsageMBSchema → MemoryUsageMB interface
  • diskUsageGBSchema → DiskUsageGB interface
  • metricsDataSchema → MetricsData interface
  • alertSchema → Alert interface

• Data parsing (src/post/lib.ts): Replaced metricsDataSchema.parse(JSON.parse(content)) with direct JSON.parse(content) as MetricsData

• Type imports: Updated all source files to use type imports for interfaces (TypeScript-only, no runtime value)

• Test updates: Modified test expecting validation errors to reflect that validation is no longer performed

Impact

• Bundle size reduced by 27,639 lines (removed 32,353, added 4,714)
• Faster build and runtime with one less dependency
• Type safety maintained at compile-time via TypeScript

Before:

import { z } from "zod";
const metricsDataSchema = z.object({...});
return metricsDataSchema.parse(JSON.parse(content));

After:

interface MetricsData {...}
return JSON.parse(content) as MetricsData;