Add synthetic import fixture data for muse agent evaluation (hop D prep)
14 segments across 6 import streams in fixture day 20260101:
- import.chatgpt (3 segments): Python async debugging conversation
- import.claude (3 segments): Event sourcing schema design conversation
- import.gemini (2 segments): Container orchestration comparison
- import.ics (2 segments): Founder calendar events (standup, investor 1:1, product review)
- import.obsidian (2 segments): Trust architecture notes, book recommendations
- import.kindle (2 segments): Hamming + Ostrom reading highlights
All segments validated: correct stream.json markers, valid JSONL/markdown content,
cluster module discovers and loads all 14 segments with proper source counts.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>