docs: Add review discipline guidelines to CLAUDE.md

[zmanian]

Summary

• Codifies lessons learned from Illia's review fixes on the libSQL backend PR (feat: add libSQL/Turso embedded database backend #47) -- patterns we missed that should be caught systematically going forward
• Bans .expect() alongside .unwrap() in production code, adds mechanical grep checks
• New "Review & Fix Discipline" section: fix all pattern instances not just the flagged one, propagate architectural changes to satellite types, schema translation must include indexes and seed data, feature flag testing in isolation

Test plan

• Verify CLAUDE.md renders correctly on GitHub
• No code changes, documentation only

Generated with Claude Code

[gemini-code-assist]

Summary of Changes

Hello @zmanian, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request introduces significant updates to the project's documentation, specifically enhancing the CLAUDE.md file. The primary goal is to codify lessons learned from past code reviews into actionable guidelines, improving code quality and consistency across the codebase. It focuses on stricter error handling practices and establishes a new 'Review & Fix Discipline' section to guide developers in addressing issues more comprehensively.

Highlights

• Error Handling Guidelines Updated: The documentation now explicitly bans the use of .expect() in production code, alongside .unwrap(), and recommends mechanical grep checks for both before committing.
• New Review & Fix Discipline Section: A comprehensive new section has been added, outlining best practices for code review and bug fixing. This includes fixing patterns across the codebase, propagating architectural changes to related types, ensuring thorough schema translation (including indexes and seed data), and isolated testing for feature flags.

Changelog

• CLAUDE.md
  • Updated error handling guidelines to include .expect() alongside .unwrap() as forbidden in production code.
  • Added a new guideline to grep for .unwrap() and .expect() before committing.
  • Introduced a new top-level section titled 'Review & Fix Discipline' with several sub-sections.

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[gemini-code-assist]

Code Review

This pull request significantly improves the development guidelines in CLAUDE.md by codifying important review and fix disciplines. The explicit ban on .expect() alongside .unwrap() in production code is a great step for robustness. The new 'Review & Fix Discipline' section provides excellent, practical advice on holistic bug fixing, handling architectural changes, schema migrations, and feature flag testing. I've added one minor suggestion to refine one of the grep commands for mechanical verification to make it more concise and robust. Overall, these are valuable additions that will help maintain code quality and consistency.