feat(network-monitor): improve Network Session logging performance

[ajinumoto]

Summary

• Split network session persistence into @MainActor manager and @ModelActor store.
• Move SwiftData container/context work off main actor to reduce session history persistence overhead.
• Replace SwiftData session-request relationship with sessionID lookup and Sendable record DTOs for UI reads.
• Update session history and request list screens to fetch persisted records asynchronously.

Main-thread load dropped significantly, with cycles reduced by about 50%: 789.31M → 395.50M.

Type of change

• Fix
• Feature
• Refactor
• Docs
• CI/CD

Test plan

• Unit tests updated
• Manual testing completed
• CI passing

Manual test steps

1. Enable Network Session Persistence beta feature.
2. Capture several HTTP requests and confirm session history shows request count and duration.
3. Open a saved session, search requests, and verify request detail still renders correctly.

Screenshots / recordings (if applicable)

This performance study uses a controlled concurrent-load method by executing 200 simultaneous requests in a TaskGroup against the same endpoint, with short-circuit mode enabled to remove external network/server variability and keep response behavior deterministic

Before:


After:

Checklist

• I reviewed my own changes
• I updated docs when needed
• I considered backward compatibility