setup: .claude/rules/grepai-first.md synced unconditionally even when grepai MCP is not configured

[Stashub]

Summary

When /brewcode:setup runs on a system without grepai configured,
the SessionStart hook correctly detects this:

SessionStart:startup says: grepai: not configured

Nevertheless, setup synchronizes .claude/rules/grepai-first.md into
the project. The rule contains a directive that every subagent reads:

FIRST grepai mcp for code exploration. Params → MCP descriptions.

Agents receive instructions to use a non-existent MCP server. This
pollutes every agent's prompt with a dead directive.

Root cause

brewcode/skills/setup/scripts/setup.sh (around lines 97-99):

# grepai-first: always sync (plugin-managed rule)
if [ -f "$PLUGIN_TEMPLATES/rules/grepai-first.md.template" ]; then
  sync_template "$PLUGIN_TEMPLATES/rules/grepai-first.md.template" \
                ".claude/rules/grepai-first.md"
fi

The "always sync" comment is explicit: the script ignores grepai
availability. No grepai_configured helper exists anywhere in
setup.sh — grepai detection lives only in the SessionStart hook,
not in setup itself.

Environment

• Claude Code: v2.1.107
• Plugin: claude-brewcode 3.5.2
• OS: Windows 11 Pro, MSYS2 (grepai MCP not installed)

Reproduction

1. Confirm grepai is not configured (SessionStart log shows
   grepai: not configured).
2. Run /brewcode:setup.
3. Open .claude/rules/grepai-first.md — exists with live
   directives referencing a missing tool.

Expected

Either:

1. Skip syncing when grepai is not configured.
2. Remove an existing grepai-first.md if grepai becomes
   unavailable between setup runs.
3. Render the file with a conditional header: "This rule is inactive
   because grepai MCP is not configured in this environment."

Proposed fix

Add a grepai detection helper to setup.sh. The SessionStart hook
already performs this check — the logic can be extracted or
duplicated:

grepai_configured() {
  # Reuse the same detection the SessionStart hook uses.
  # Adjust the concrete check to match the actual MCP registry
  # location in your target environments.
  [ -f "$HOME/.claude/mcp.json" ] && grep -q '"grepai"' "$HOME/.claude/mcp.json"
}

Then wrap the grepai-first.md sync:

if grepai_configured && [ -f "$PLUGIN_TEMPLATES/rules/grepai-first.md.template" ]; then
  sync_template "$PLUGIN_TEMPLATES/rules/grepai-first.md.template" \
                ".claude/rules/grepai-first.md"
elif [ -f ".claude/rules/grepai-first.md" ]; then
  rm ".claude/rules/grepai-first.md"
fi

The exact MCP config path may differ per environment — the author
knows the correct location better. The pattern is what matters:
check before sync, clean up on absence.

Impact

Low severity by itself — Claude usually recognizes the tool is
missing and falls back to native Grep. But the dead directive
pollutes every agent's prompt and undermines the credibility of
.claude/rules/ as a source of applicable guidance.