chore: add CLAUDE.md and project memory for Claude Code

Add CLAUDE.md with project guidance for adding new LLM providers.
Add .claude/memory/ with feedback rules:
- Preserve markdown quotes when editing
- Save memories in project directory

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

CLAUDE.md

@@ -0,0 +1,22 @@
+# CLAUDE.md
+
+This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.
+
+## Project Overview
+
+This is a curated list of budget-friendly LLM providers. It's a documentation-only project (no code) maintained in README.md.
+
+## Adding New Providers
+
+When adding a new provider to README.md, include:
+- Provider name with link to homepage
+- Pricing/plan details (if applicable)
+- Free tier limits or usage restrictions
+- Source link for verification
+- Footnote with the date information was verified (format: `[^providername]: Check at MMM DD YYYY`)
+
+## Structure
+
+README.md is organized into sections:
+- **Providers support coding plans**: Subscription-based coding plans
+- **Free providers**: Providers with free tiers or trials