feat(cockpit): enter Cockpit with only the ridden aircraft's layer on

Cockpit entry no longer needs Contacts or both flight feeds: a civilian
aircraft needs Live Flights, a military one Military Flights. Contacts and
every other layer can be turned on or off before or during a session, and
turning off the ridden layer ends it. A Context mode change in flight still
blocks entry.

When the other air feed is off, Live Signals and the Contact card say
FLIGHTS FEED OFF or MILITARY FEED OFF · PARTIAL PICTURE instead of
presenting a partial picture as complete. Voice refuses entry with
subject-layer-off rather than contacts-inactive, and its tool description
says Contacts is not required.

Double-clicking the followed aircraft enters Cockpit through the same gate.
The Cockpit takes the scene's double-click before Cesium's stock handler,
which would otherwise untrack a followed aircraft whose model is a
primitive. The entry also shows under the Intel HUD readout, sharing the
Contacts button's face. A test keeps the classes the Cockpit adds to the
body from matching another element's rule.

scripts/package-boundaries.json

@@ -39,6 +39,9 @@
       "src/ui/views/panels/CockpitBriefing.vue",
       "src/ui/views/panels/CockpitContext.vue",
       "src/ui/views/panels/CockpitRoute.vue",
+      "src/ui/cockpitPresentation.js",
+      "src/data/headingDegrees.js",
+      "src/data/distanceFormat.js",
       "src/ui/views/panels/CockpitRollingValue.vue",
       "src/ui/views/panels/CockpitSignalList.vue",
       "src/ui/views/panels/CockpitUtilityControls.vue",
@@ -866,6 +869,7 @@
       "src/ui/cockpitDisplayPortal.js",
       "src/ui/displayPanelScroll.js",
       "src/ui/cockpitInput.js",
+      "src/data/inputOwnership.js",
       "src/ui/cockpitInstruments.js",
       "src/ui/cockpitLayout.js",
       "src/ui/cockpitPresentation.js",
@@ -992,6 +996,7 @@
       "src/ui/cockpitDisplayPortal.js",
       "src/ui/displayPanelScroll.js",
       "src/ui/cockpitInput.js",
+      "src/data/inputOwnership.js",
       "src/ui/cockpitInstruments.js",
       "src/ui/cockpitLayout.js",
       "src/ui/cockpitPresentation.js",