Improve industry news alert format for engagement

[bokelley]

Summary

• Replace verbose priority headers (":star: HIGH - Agentic AI in Advertising") with clean article title as the Slack header
• Change "addie_notes" prompt from explanatory to engagement-driving "addie_take" with spicy, opinionated takes that end with discussion prompts
• Remove summary section from Slack alerts (Slack unrolls links anyway)
• Remove tags from Slack output (kept in DB for filtering)
• Fix HTML entity decoding in RSS feed titles (' → ')
• Reduce false positives in agentic/AdCP mention detection by only checking original article content, not AI-generated summaries

Before/After

Before:

:star: HIGH - Agentic AI in Advertising
Algorithm chaos and power plays close digital advertising's turbulent year
Source: PPC Land

[summary paragraph]

*Why this matters:* This article directly showcases the transformation toward agentic advertising systems...

Tags: `ai-agents` `advertising` `programmatic`

After:

Algorithm chaos and power plays close digital advertising's turbulent year
PPC Land

🤖 Big Tech is building AI agents that lock you into their walled gardens. Is open-source AdCP the antidote? What's your take?

Test plan

• Build passes
• All tests pass
• Code review completed

🤖 Generated with Claude Code