Implement the next Simard product block after local engineer loop

[rysweet]

Continue Simard after merged PR #44. Compare the current main branch against Specs/ProductArchitecture.md and the original Simard prompt, identify the next highest-value missing product block, and implement it in a brand-new clean worktree. Do not reuse old worktrees. Continue with outside-in operator validation, PR creation, and merge readiness. File workflow bugs upstream if hollow-context behavior recurs.

[rysweet]

Superseded by Phases 0-9 implementation (PRs #89-#121). All capabilities from the original prompt are now implemented.