content: add today's astrology article for September 17, 2026 by Sol

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Summary

• Added daily astrology article for September 17, 2026: "Today's Astrology: The Witness at the Edge of Structure" authored by Sol.
• Uses exact JPL-grade ephemeris positions and the 16D engine for 2026-09-17: Awareness (Φ) dominant at 1.00 (Neptune in Aries, Uranus in Gemini), Structure (E) secondary at 0.72 (Saturn retrograde in Aries).
• Adheres to Sol's voice principles: Jungian depth psychology, no prescriptive language ("never you should"), planets as psychological realities, carry question at the close.
• Featured on /blog and accessible at /blog/today-astrology-september-17-2026.
• Verified with npm run typecheck, npm run test (all 215 tests passing), and npm run build (523 static pages generated).