Add "Don't Live with Broken Windows" principle to Dotfiles Philosophy section

## Summary

Add the "Don't Live with Broken Windows" principle to the README.md Dotfiles Philosophy section to complete our core principles documentation.

## Background

The recent clojure-mcp setup script failures (#385) highlighted the importance of addressing small problems immediately before they compound into larger issues. This aligns perfectly with the "Don't Live with Broken Windows" principle from *The Pragmatic Programmer*.

## Proposed Addition

Add a fourth principle to the existing Dotfiles Philosophy section in README.md:

### Current Principles:
1. The Spilled Coffee Principle
2. The Snowball Method
3. The Versioning Mindset

### Proposed Addition:
4. **Don't Live with Broken Windows** - Fix small problems immediately (bad code, failing commands, ignored warnings) to prevent quality erosion and technical debt accumulation.

## Rationale

This principle would help establish a culture of:
- Immediate attention to visible problems (like red error logs)
- Prevention of technical debt accumulation
- Maintaining high standards consistently
- Not tolerating "small" issues that signal it's okay to let quality slide

## Implementation

Update the `## Dotfiles Philosophy` section in README.md following the same format as the existing three principles, with explanation of how this applies to dotfiles management and configuration quality.

## Related

- Fixes the mindset that allowed #385 to persist
- Establishes clear guidance for future contributors
- Complements existing principles around resilience and continuous improvement

Open README.md and locate the ## Dotfiles Philosophy section. Review the formatting and explanations of the three existing principles, then add the proposed fourth principle in the same style. Done means the section documents “Don't Live with Broken Windows” and its relevance to dotfiles quality.

Written by the indexing model from the issue text.