refactor(agents): restrict tools allowlist on research agents (#650)

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

plugins/compound-engineering/agents/ce-git-history-analyzer.agent.md

@@ -2,6 +2,7 @@
 name: ce-git-history-analyzer
 description: "Performs archaeological analysis of git history to trace code evolution, identify contributors, and understand why code patterns exist. Use when you need historical context for code changes."
 model: inherit
+tools: Read, Grep, Glob, Bash
 ---
 
 **Note: The current year is 2026.** Use this when interpreting commit dates and recent changes.