Standardize workspace resolution patterns in genie for megarepo consumers

Context

createWorkspaceDepsResolver in @overeng/genie runtime enables import-based workspace resolution where each package's pnpm-workspace.yaml.genie.ts imports its deps' package.json.genie.ts files, and the resolver does BFS to find all transitive workspace deps.

This pattern works well for single-repo setups (effect-utils with ~12 @overeng/ packages). However, megarepo consumers composing multiple repos face additional challenges:

1. Cross-repo scope mapping — packages span multiple scopes (@livestore/, @diffstream/, @overeng/, etc.) at different directory depths. The resolveWorkspacePath callback needs a scope-to-path mapping.

2. Parallel patterns — livestore currently uses a separate approach: an explicit workspaceDeps graph with resolveTransitiveDeps() instead of createWorkspaceDepsResolver. Both solve the same problem differently.

Proposal

Short-term: Converge patterns

Migrate livestore to use createWorkspaceDepsResolver (same as effect-utils), eliminating the redundant manual dep graph + transitive resolver.

Medium-term: Upstream cross-repo helpers

Add reusable helpers to genie runtime for megarepo consumers:

• Scope-path registry — declarative mapping from package name prefixes to workspace-root-relative directories:

  const scopePathMap = {
    '@livestore/': 'repos/livestore/packages/@livestore/',
    '@overeng/': 'packages/@overeng/',
  }
  

• createMegarepoWorkspaceDepsResolver — wraps createWorkspaceDepsResolver with scope-based path computation, so consumers only declare the mapping instead of writing custom resolveWorkspacePath callbacks.

• Effect-utils package registry re-export — effect-utils packages' package.json.genie.ts files need to be importable by downstream repos for BFS resolution. Consider a single re-export module.

Current Workaround

Each megarepo consumer implements their own resolveWorkspacePath with a scope map. This works but is boilerplate that could be shared.

Filed by Claude on behalf of @schickling

Start by comparing the createWorkspaceDepsResolver pattern with livestore's workspaceDeps and resolveTransitiveDeps() approach. Review the pnpm-workspace.yaml.genie.ts and package.json.genie.ts entry points, then clarify the intended scope-map helper and migration boundaries. Done requires an agreed reusable cross-repo resolver design and a defined convergence plan.