docs: Add primary and supporting taglines

Add clear positioning taglines to reinforce investment philosophy:
- Primary tagline (README top): "AI-powered investment research for
  patient, systematic investors."
- Supporting tagline (footers): "Smarter screens, not faster trades."

Placement:
- README.md: Primary tagline under badges (prime real estate),
  supporting tagline in footer
- docs/presets.md: Supporting tagline in footer (user-facing)
- docs/fields.md: Supporting tagline in footer (user-facing)
- docs/development.md: No footer (technical, for contributors)

The taglines work together to communicate value proposition and
anti-day-trading positioning while being memorable and CEO-friendly.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

Author: bearmug

README.md

@@ -12,6 +12,8 @@
 
 **Unofficial** Model Context Protocol (MCP) server for TradingView's stock screener API.
 
+### AI-powered investment research for patient, systematic investors.
+
 </div>
 
 ---
@@ -317,4 +319,6 @@ This is an unofficial tool and is not affiliated with, endorsed by, or connected
 
 ---
 
+**Smarter screens, not faster trades.**
+
 Built with ❤️ using the [Model Context Protocol](https://modelcontextprotocol.io)

docs/fields.md

@@ -793,3 +793,7 @@ Many financial metrics have multiple time period variants. Understanding these i
 - [Preset Strategies](presets.md) - Pre-configured screening strategies
 - [Development Guide](development.md) - How to add new fields
 - [Main README](../README.md) - Getting started guide
+
+---
+
+**Smarter screens, not faster trades.**

docs/presets.md

@@ -427,3 +427,7 @@ Screen for value stocks with P/E under 15
 - [Field Reference](fields.md) - Complete list of all 75+ available fields
 - [Development Guide](development.md) - How to create custom presets
 - [Quick Start Guide](../README.md#quick-start) - Custom screening examples
+
+---
+
+**Smarter screens, not faster trades.**