feat: add stetkeep protocol agents (brain-router, craft-specialist, perf-specialist)

[chanjoongx]

Summary

Adds three protocol-driven agents from stetkeep, an XML protocol framework + false-positive catalog for Claude Code.

Agents added

09 — Meta & Orchestration

• brain-router: top-level orchestrator that classifies MD files and routes compound/ambiguous code-quality requests to the right specialist. Triggers on "refactor", "optimize", "full checkup", etc. Uses the Agent tool to actually spawn craft-specialist or perf-specialist — it does not just advise, it delegates.

04 — Quality & Security

• craft-specialist: structural refactor agent restricted to Read/Grep/Glob/Edit/Bash — no Write tool, so it cannot create new files. Follows CRAFT.md's 20 anti-patterns (A1–A20) and an 8-entry false-positive catalog.
• perf-specialist: measurement-first performance agent with a hard gate — refuses any optimization without baseline Lighthouse/Profiler numbers. Same tool restriction as craft-specialist. Includes 8-entry false-positive catalog for patterns V8/React already handle internally.

What makes these different from existing agents

• vs code-reviewer: craft-specialist is narrower — behavior-preserving refactor only, with a false-positive catalog that explicitly lists patterns Claude must NOT flag (profiled hot paths, generated files, framework idioms, compliance constants).
• vs performance-engineer: perf-specialist has a hard measurement gate. No numbers = no action. It will refuse and ask the user to run Lighthouse/Profiler first.
• False-positive catalog: 16 total entries (8 CRAFT + 8 PERF) encode patterns that look like anti-patterns but aren't — this prevents "helpful" regressions that other agents don't guard against.

Note on agent file length

These agents are intentionally concise (~50 lines vs the typical 200+ line format here). The reason: they reference external XML protocol files (CRAFT.md / PERF.md / BRAIN.md) that ship with stetkeep and contain the full behavioral specification. The agent files act as controllers; the protocol files carry the detail. Happy to expand inline if the convention here requires it.

Note on model: inherit

These agents use model: inherit rather than sonnet/opus to respect whatever model the user's session is running. Functionally equivalent for sonnet users; easily overridden by editing the frontmatter.

Note on Agent tool in brain-router

brain-router uses the Agent tool because it actually spawns craft-specialist or perf-specialist as subagents — it does not just recommend delegation. This is standard Claude Code 2026 subagent spawning behavior.

Installation

Full framework (recommended): npx stetkeep install — copies protocol files (CRAFT.md, PERF.md, BRAIN.md) + these agents into the user's project.
Standalone: copy the agent files directly; add CRAFT.md / PERF.md to the project root from the stetkeep repo.