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.

CONTEXT.md

@@ -208,8 +208,8 @@ enforces the separation **without ever destroying the user's real state.**
   `TrackFX_SetOffline(track, fx, true)` for **each** FX (reclaim CPU). Full CPU-park
   is the deliberate choice over mix-removal-only.
 - **Never touches `B_MUTE` / `I_SOLO`.** The tool owns only visibility,
-  `B_MAINSEND`, `I_FXEN`, and per-FX offline — and only on tracks it tagged. User
-  mute/solo survives every toggle untouched.
+  `B_MAINSEND`, `I_FXEN`, and per-FX offline — on every managed leaf, tagged or
+  untagged. User mute/solo survives every toggle untouched.
 - **Persistence.** Membership index + last-active mode + per-track flag snapshots
   ride in the existing `"reasampler"` project ext-state namespace and travel with
   the `.rpp`. On project open, reapply the active mode's visibility + processing.
@@ -295,8 +295,11 @@ togglable per selection.
   path in review.
 - **Never touch mute/solo.** Any code path reading/writing `B_MUTE` / `I_SOLO` is a
   bug.
-- **Never touch untagged tracks.** The tool acts only on tracks it tagged (plus
-  derived parents' *visibility*); it never parks or restores a track it doesn't own.
+- **Every leaf is managed.** The mode system owns all leaf tracks: an untagged leaf
+  is an Arrange member, and when the active mode is not Arrange it is fully parked
+  and snapshot-restored exactly like a tagged leaf out of its mode. **show-both** is
+  the only way to opt a leaf out of parking. (Parents stay visibility-only, master
+  is never touched — see below.)
 - **Restore from snapshot, never to a default.** No hardcoded "on" restores.
 - **Verify API names** against the SDK header before use.