chore: update pi-subagents to 0.74.0

[BakerSean168]

Summary

• update pi-subagents from 0.73.1 to 0.74.0
• pull undici from 8.10.0 to 8.10.2, outside the reported advisory ranges
• update the architecture dependency contract

Validation

• npm run check: 39/39 passed
• npm audit: 0 vulnerabilities
• npm pack --dry-run: Pi-native package boundary unchanged
• deterministic public-boundary probe confirms named workflows remain supported and explicit named-workflow capacity overrides still fail closed
• isolated Pi profile with pi-subagents 0.74.0 auto-loaded ForgeFlow without --extension and completed forgeflow.review with clean/OK typed-gate verdict

The 0.74 breaking change affects model-facing raw workflowScript/workflowScriptPath usage; ForgeFlow uses named workflow resources and does not depend on those removed fields.