First M2 vertical slice: CanonLog -> HTTP -> /dm/narrate -> prose ->
screen -> fact-harvest, with a §13 degraded-DM fallback on any failure.
Pure DmService core behind an injectable DmTransport seam (headless-
testable); throwaway harness scene; one authored fallback line under
client/content (renderer owns the file's home).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
