[codex] Add long agent loop Electron E2E

[aj47]

Summary

• Add an opt-in real Electron E2E for three concurrent long-running agent sessions through the desktop UI.
• Add a deterministic sandbox MCP fixture/server with delayed tools and hidden evidence requirements.
• Add isolated app-data/user-data overrides so the E2E does not mutate normal desktop state.
• Document prerequisites, command, artifacts, and expected runtime for the long suite.

Validation

• pnpm --filter @dotagents/desktop run typecheck:node
• pnpm --filter @dotagents/desktop exec vitest run src/main/agent-loop-long-sandbox-fixture.test.ts
• LONG_AGENT_LOOP_E2E=1 /usr/bin/time -p pnpm --filter @dotagents/desktop run test:e2e:agent-loop-long
  • Passed with artifacts in apps/desktop/tmp/e2e-agent-loop/2026-05-25T01-08-23-871Z/
  • Shell wall time: 159.68s
  • Runner total: 158.631s
  • Session durations: 115.269s, 135.299s, 150.432s
  • Tool calls per session: 8, 9, 10
  • Session switch latency: min 6ms, max 25ms, avg 10.05ms

Notes

This suite remains opt-in behind LONG_AGENT_LOOP_E2E=1 and is not wired into normal tests, typecheck, or CI.