docs(design-view): correct reversed untagged-track invariant to "every leaf is managed"

Untagged = Arrange member, fully parked in non-Arrange modes like a tagged
leaf; show-both opts out. Master/parents/mute-solo caveats preserved.

docs/product/design-view.md

@@ -112,8 +112,10 @@ truth and changes underneath us).
 
 ## What a toggle actually does (the parking contract)
 
-Toggling to mode M partitions tagged leaves into **active** (in M, or show-both)
-and **inactive** (tagged into some other mode, not M). For each track:
+Toggling to mode M partitions **every** leaf into **active** (belongs to M, or
+show-both) and **inactive** (belongs to some other mode — tagged elsewhere, or
+untagged/Arrange when M is not Arrange). Untagged leaves are Arrange members and
+park identically to tagged ones; there is no unmanaged leaf. For each track:
 
 **Active leaves** and **derived-visible parents** → restored to their snapshot
 values (see restore contract) and shown.
@@ -138,8 +140,9 @@ of the CPU reclaim, not a bug. It must be documented at the toggle affordance so
 the user isn't surprised.
 
 **Never touched:** `B_MUTE` and `I_SOLO`. The tool owns visibility, `B_MAINSEND`,
-`I_FXEN`, and FX-offline — nothing else — and only on tracks it has tagged. The
-user's mute/solo survives every toggle, untouched. This is the exact analog of the
+`I_FXEN`, and FX-offline — nothing else — across every managed leaf, tagged or
+untagged. The user's mute/solo survives every toggle, untouched. This is the exact
+analog of the
 capture pillar's non-destructive invariant: **the tool never destroys the user's
 real state to do its job.**