Reconcile the divergent house-of-quality work. Conflict in DESIGN.md
was the preamble's default \qfdHdrH (2.6 from the canonical resync vs
3.5 from the incoming label-overflow fix): keep the preamble at the
canonical 2.6 and move the 3.5 sizing override into the Macroplan
house block where the other house-specific dims live. Same render.
The embedded preamble had drifted from the qfd skill's reference: it
lacked the title-block machinery, section comments, and sizing notes.
Replace it verbatim so future edits don't fight stale scaffolding.
House now leads the document as the quick-reference overview; numbered
sections follow as the prose backing. \qfdHdrH raised 2.6 → 3.5 so F2/F3
labels no longer overflow the roof. F1 legibility target tightened to ≤1s
throughout (§2 table, §3 cascade, tikz basement, §7 budget).
