Make process diagnostics parsing more idiomatic Effect

[cursor]

What Changed

• Decode Windows process diagnostics JSON with Schema.fromJsonString and per-record Schema parsing instead of JSON.parse plus ad-hoc record traversal.
• Normalize optional/null Windows process fields through Option and keep the process-query timeout as an effect/Duration.
• Updated the adjacent ProcessDiagnostics tests to use assert from @effect/vitest and added a mocked Windows ChildProcessSpawner test for the Schema decoding path.

Why

This keeps process diagnostics easier to test and maintain with native Effect primitives while preserving the existing behavior of skipping malformed Windows records instead of failing the whole diagnostics read.

UI Changes

Not applicable; server diagnostics/test-only behavior, no UI changes.

Checklist

• This PR is small and focused
• I explained what changed and why
• I included before/after screenshots for any UI changes
• I included a video for animation/interaction changes

Verification:

• PATH="/home/ubuntu/.nvm/versions/node/v24.18.0/bin:$PATH" pnpm --dir apps/server run test src/diagnostics/ProcessDiagnostics.test.ts (7 tests passed)
• PATH="/home/ubuntu/.nvm/versions/node/v24.18.0/bin:$PATH" pnpm exec vp check (passed with existing warnings)
• PATH="/home/ubuntu/.nvm/versions/node/v24.18.0/bin:$PATH" pnpm exec vp run typecheck (passed)

  

Note

Refactor Windows process diagnostics parsing to use Effect Schema

• Replaces ad-hoc JSON parsing in parseWindowsProcessRows with schema-driven decoding via WindowsProcessRecord and WindowsProcessJson schemas in ProcessDiagnostics.ts.
• Adds normalizeWindowsProcessRecord to validate PIDs, derive command from CommandLine or Name, default empty Status to 'Live', clamp negative CPU%, and round WorkingSetSize.
• Invalid records now return Option.none and are skipped silently; invalid JSON yields an empty array instead of throwing.
• Replaces PROCESS_QUERY_TIMEOUT_MS with a Duration-based constant passed directly to Effect.timeoutOption.
• Behavioral Change: whitespace-only Status values now default to 'Live'; previously they would propagate as-is.

^{Macroscope summarized 5b499fd.}