Move the landed filter-voice-path track from PLAN.md into COMPLETED.md with full
narrative (quantizer removal, editor floor raise). Mark Θ-W2 fully landed, matching
W1's phrasing; fix a stale forward reference.
Split root CLAUDE.md into 19 per-directory files scoped to their source area.
Roll v0 history into docs/ARCHIVE.md; retire CONTEXT.md, CONTEXT-ARCHIVE.md,
PLAN.md, COMPLETED.md. Move plan docs under docs/. Rescue 9 live deferrals
into docs/TODO.md.