Extract per-package architectural synthesis from Go codebase

Architectural review insight (coupling risk, latent contracts, layering) layered on top of deterministic go list/go doc baseline for medium-to-large codebases.

• · list of Go package paths (via args.packages)

• · markdown report per package with 4 sections: dependency_summary, public_surface_summary, architectural_synthesis (layer, role, fan_in_implication, domain_boundary), claims_beyond_baseline

• · Go codebase with readable package sources
• · packages list injected via args

• · parallel agent cost only justified at high package count; scales poorly for small repos
• · non-deterministic if agents add timestamps to output
• · claims beyond baseline may be speculative or incomplete

• · determinism note: package list injected, no wall-clock/random in body
• · honest fallback: agents return 'NONE — reducible to baseline' if no genuine inference
• · read-only enforcement via agentType Explore