Add X/Twitter intelligence analyst agent

[kriptoburak]

What does this PR do?

Adds a Marketing Division agent for X/Twitter intelligence analysis. The agent focuses on public or authorized data, evidence preservation, query planning, monitoring thresholds, and action-oriented briefs. It declares Xquik as an external service dependency while keeping the workflow useful without API access.

Agent Information (if adding/modifying an agent)

• Agent Name: X/Twitter Intelligence Analyst
• Category: Marketing
• Specialty: Social listening, trend detection, brand risk monitoring, competitor and audience intelligence on X/Twitter

Checklist

• Follows the agent template structure from CONTRIBUTING.md
• Includes YAML frontmatter with name, description, color
• Has concrete code/template examples (for new agents)
• Tested in real scenarios - static validation only
• Proofread and formatted correctly

Validation

• ./scripts/lint-agents.sh marketing/marketing-x-twitter-intelligence-analyst.md
• git diff --cached --check
• Checked the README local link and https://xquik.com