Design the stable v0.3 consumer API

[Aaronontheweb]

Summary

• treat stable v0.2 as the compatibility boundary and all v0.3 alphas as disposable previews
• keep the Syntax, Commands, and Clauses ingestion lanes while replacing sparse joins and mutable property bags
• specify parser-owned joined arguments plus closed value-domain, redirect-source, and redirect-analysis families
• prune condition and branch vocabulary that stable v0.3 never emits
• reopen corrected-implementation API, corpus, build, pack, and downstream verification gates

Consumer impact

Netclaw can migrate directly from alpha.5 without compatibility shims. It will iterate analyzed arguments without correlating indices and pattern-match valid value and redirect alternatives without revalidating impossible public shapes. Executable grammar, protected paths, hard deny, approval identity, and final policy remain consumer-owned.

Validation

• openspec validate v0-3-structured-shell-analysis --strict
• dotnet build -c Release (0 warnings)
• dotnet test -c Release --no-build (2,867 passed)
• pwsh ./scripts/Add-FileHeaders.ps1 -Verify
• git diff --check
• adversarial API review: PASS after three revision rounds