Commands Layer — Create .opencode/commands/ slash commands

[striderZA]

Summary

AGENTS.md references 72 slash commands but .opencode/commands/ doesn't exist. Create thin composition commands that route to skills + agents.

Design

Each command is a markdown file with:

---
description: One-line summary
skills: [list of skill directories to load]
agents: [agent to delegate to]
args: [positional argument descriptions]
---
Command workflow steps

Command Categories

• Onboarding (5): start, help, project-stage-detect, setup-engine, init-template
• Design (6): brainstorm, map-systems, design-system, quick-design, design-review, review-all-gdds
• Architecture (4): create-architecture, architecture-decision, architecture-review, create-control-manifest
• Stories (6): create-epics, create-stories, story-readiness, dev-story, story-done, code-review
• QA (8): qa-plan, smoke-check, soak-test, regression-suite, test-setup, test-helpers, test-evidence-review, test-flakiness
• Prototyping (2): prototype, reverse-document
• Team (8): team-combat, team-narrative, team-ui, team-level, team-audio, team-polish, team-qa, team-release
• Release (6): sprint-plan, sprint-status, milestone-review, release-checklist, launch-checklist, retrospective
• Ops (5): hotfix, day-one-patch, bug-report, bug-triage, security-audit

Acceptance Criteria

• .opencode/commands/ directory created with command files
• At least 30 commands implemented for v0.4.0
• Each command has description, skills list, agent routing, and workflow steps
• OpenCode recognizes and lists commands on / invocation