Use idiomatic Effect filesystem and duration APIs

[cursor]

What Changed

• Replaced node:fs/promises.realpath wrappers in WorkspaceFileSystem.readFile with the injected Effect FileSystem.realPath service.
• Added a structured assertion for the resulting PlatformError details in the workspace read failure test.
• Replaced telemetry's raw Effect.sleep(1000) with ANALYTICS_FLUSH_INTERVAL = Duration.seconds(1).
• Added a TestClock-backed telemetry test that advances the Effect clock and verifies the buffered event is flushed.

Why

This keeps production Effect code on Effect-native services and duration values, making filesystem behavior easier to layer/mock and scheduled telemetry behavior deterministic under TestClock.

UI Changes

Not applicable.

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="$HOME/.nvm/versions/node/v24.18.0/bin:$PATH" pnpm exec vp test apps/server/src/workspace/WorkspaceFileSystem.test.ts apps/server/src/telemetry/AnalyticsService.test.ts
• PATH="$HOME/.nvm/versions/node/v24.18.0/bin:$PATH" pnpm exec vp check
• PATH="$HOME/.nvm/versions/node/v24.18.0/bin:$PATH" pnpm exec vp run typecheck

  

Note

Use idiomatic Effect filesystem and duration APIs in WorkspaceFileSystem and AnalyticsService

• Replaces NodeFSP.realpath wrapped in Effect.tryPromise with FileSystem.realPath in WorkspaceFileSystem.ts; errors now map to WorkspaceFileSystemOperationError with a PlatformError cause instead of a raw NodeJS.ErrnoException.
• Exports ANALYTICS_FLUSH_INTERVAL as Duration.seconds(1) in AnalyticsService.ts and replaces the hardcoded 1000ms sleep with Effect.sleep(ANALYTICS_FLUSH_INTERVAL).
• Adds a new test in AnalyticsService.test.ts that verifies periodic flush behavior using TestClock.
• Behavioral Change: WorkspaceFileSystem.readFile errors on path resolution now carry a PlatformError with reason._tag === 'NotFound' and reason.method === 'realPath' instead of a Node errno object.

^{Macroscope summarized 7e514b6.}