v1.6.1

Bug fixes, bloat removal, and stale reference updates

Fixed (17 issues across 11 files)

Bugs (6):

• Missing import os and from fastapi.responses import JSONResponse in deployment.md FastAPI examples
• Hardcoded POSTGRES_PASSWORD: agent in docker-compose replaced with ${POSTGRES_PASSWORD}
• Deprecated from langchain.tools import tool → from langchain_core.tools import tool in entity-resolution.md
• Incorrect claim that sed has a -F flag in text-tools.md
• Duplicate conflicting GPT-4o cost row in entity-resolution.md
• Stale model string gpt-4o-2024-08-06 → gpt-4o in structured-classification.md

Bloat removed (~80 lines):

• Three-way failure modes duplication consolidated into patterns.md as single source of truth
• Metrics table duplication in deployment.md replaced with cross-reference
• Eval content duplication in evals.md and production.md replaced with cross-references

Stale references updated (5):

• "GPT-5-nano" → "GPT-4o-mini" in binary-evals.md
• "Claude-Opus-4" → "Claude Opus" in llm-as-judge.md
• "as of 2025" → "as of early 2026" in prompt-structuring.md
• Removed stale "GA Q1 2026" from frameworks.md
• Mastra license "MIT-like" → "Elastic License 2.0 (ELv2)" in frameworks.md

Other:

• Added single-process caveat to in-memory rate limiter in production.md
• "with Sonnet" → "with Claude Sonnet" in langchain-langgraph.md

Net: 14 files changed, 53 insertions, 93 deletions. Validation passes.