Build-time template injection for repeated command snippets

[dean0x]

Problem

Command markdown files (resolve.md, plan.md, code-review.md, etc.) contain repeated boilerplate sections that must stay in sync manually. The most prominent example is the knowledge-loading phase (~3 lines repeated across 10 surfaces), but the pattern applies to any shared orchestration step.

These files must be self-contained at runtime (Claude reads each in isolation — no import mechanism), so the duplication is currently unavoidable.

Proposed Solution

Extend the build system (npm run build / devflow init) to support template expansion in command files:

1. Define shared snippets in shared/snippets/ (e.g., knowledge-loading-phase.md)
2. Command source files use a marker like <!-- inject:knowledge-loading-phase -->
3. Build step expands markers into full content before copying to install paths

This mirrors how shared/skills/ and shared/agents/ already work — single source of truth in shared/, distributed at build time.

Context

• Identified during PR fix(v2): three project-knowledge ship-blockers #182 review walkthrough (Issue Evaluate: Should /debug command have dedicated sub-agent? #11)
• The knowledge-loading phase is the motivating case: KNOWLEDGE_CONTEXT=$(node ...) + surrounding prose × 10 surfaces
• Related: post-release knowledge architecture improvements may reduce this specific case (see memory: knowledge-architecture-followup)
• The template injection pattern would generalize to any repeated orchestration step

Scope

Post-v2 release. Low priority — current duplication is manageable and the command set is stable.

[dean0x]

Additional candidate for build-time injection: the ## Apply Knowledge section in consumer agents (designer, reviewer, resolver, scrutinizer). Currently each agent has a near-identical section — could be composed from a shared snippet during npm run build.