docs: record Θ-W7, the arc-and-spline antialiasing fix, and file the scaled-fallback deferral

docs/TODO.md

@@ -309,3 +309,35 @@ been observed to be wrong, only unverified.
 **Done looks like.** Either `IPlugViewContentScaleSupport` is implemented and the
 AA/uniform-width guarantees are re-verified at a scaled client size, or a decision is
 recorded that host-side resampling of the rasterized output is an accepted tradeoff.
+
+## The analytic stroker's scaled fallback path is unexercised
+
+**Context (what shipped — Θ-W7-T1, arc-and-spline-aa).** `blendCanvas`
+(`shell/instrument/editor_stroke.cpp`) guards against `LICE_EXT_GET_SCALING` being
+active by falling back to a per-pixel `LICE_PutPixel` path, because the primary raw-bits
+path derives its geometry from logical width/height while writing through
+`getRowSpan()` — under an active scale that would misplace the stroke or write past the
+DIB allocation.
+
+**The wart.** Nothing calls `SET_SCALING` today, so the fallback path never runs. Under
+an active scale it would rasterize the coverage mask at *logical* resolution with each
+logical pixel expanded to a scale-sized block — geometrically correct but blocky rather
+than resolution-independent. This connects to the already-filed high-DPI host-scaling
+deferral above; cross-referenced here rather than duplicated.
+
+**Intended fix.** Not proposed — same shape as the host-scaling deferral above:
+implementing (or verifying) genuine scale-aware rasterization is the shape of a fix, not
+yet scoped.
+
+**The constraint the fix MUST handle.** Not yet known — no design work has started, and
+none can usefully start before the host-scaling deferral above is resolved, since that
+is what would first exercise this path.
+
+**Priority / risk.** Low / deferred. Recorded as a gap, not a defect: the fallback is
+guarded, correct-but-blocky rather than wrong, and unreached by anything in the tree
+today.
+
+**Done looks like.** Either the fallback path is exercised under a genuinely scaled
+bitmap and confirmed to place the stroke correctly, or it is redesigned to rasterize at
+physical rather than logical resolution once `IPlugViewContentScaleSupport` (or
+equivalent) makes scaling real.