Add aps next orchestration command

[joshuaboys]

Summary

• Add aps next [module] to resolve the next Ready APS work item from markdown plans.
• Parse module work items, statuses, dependencies, and cross-module dependency state without adding a separate datastore.
• Add shell regression fixtures for same-module dependencies, cross-module dependencies, wrapped dependency lists, unknown dependencies, and malformed statuses.

APS Work Items

• ORCH-001: Implement aps next command (In Progress)

Test Plan

• bash test/orchestrate.sh
• bash -n bin/aps lib/orchestrate.sh test/orchestrate.sh
• npm run lint
• npm run validate (passes with existing W003 cross-file/decision dependency warnings)