zip-doc audit: last stale key claim + a keylight-stub warning at cut time

Full audit of every user-facing artifact in a freshly cut zip (33 checks, all
passing -- README substitutions/controls/migration story, CONTROLS.txt ASCII
flatten, CONTROLS.html loader + wrap, launchers byte-identical, exe carries the
migration):

  * README's intro still said 'Press V any time to toggle the external camera'
    -- the one key claim outside the rewritten controls block, stale for every
    fresh/migrated install since the board took V.  Backtick now.
  * mkdist warns at cut time when the exe carries the KEYLIGHT STUB (build
    machine's SDK < 10.0.22000), because the README promises the RGB feature
    -- nobody should ship a stub build believing that promise ships with it.

The audit zip itself was deleted after verification: its version stamp predates
today's doc commits, and a release cut should rebuild the exe at final HEAD
first (the 554 procedure).

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

players/README.txt

@@ -44,7 +44,8 @@ never uploaded and only exists on your machine.
 You start INSIDE the cockpit with the pod's MFD panels composited
 around the view (one window).  The red MFD buttons, radar rails and
 joystick buttons are all MOUSE-CLICKABLE -- right-click a button to
-latch it held.  Press V any time to toggle the external camera.
+latch it held.  Press ` (backtick) any time to toggle the external
+camera.
 
 CONTROLS (keyboard) -- NEW DEFAULT LAYOUT THIS BUILD:
   The keyboard IS the cockpit button board now: the letter and number

tools/mkdist.py

@@ -75,6 +75,22 @@ def main():
     zpath = os.path.join(outdir, name + ".zip")
 
     exes = ["build/Release/btl4.exe"]
+
+    # HONESTY CHECK (2026-07-26): the RGB keylight compiles to a dormant stub
+    # on machines whose Windows SDK is too old (< 10.0.22000 -- see
+    # CMakeLists), and the README promises the feature.  Say so at cut time,
+    # so nobody ships a stub build believing the promise.
+    try:
+        with open(exes[0], "rb") as f:
+            if b"built without Dynamic Lighting support" in f.read():
+                print("  *** NOTE: this exe carries the KEYLIGHT STUB (build "
+                      "machine's SDK too old).  The README's RGB-keyboard "
+                      "feature will be dormant in this zip -- build on a "
+                      "machine with SDK >= 10.0.22000 to ship the real "
+                      "mirror. ***")
+    except OSError:
+        pass
+
     bats = ["players/play_solo.bat", "players/join.bat", "players/join_lan.bat",
             "players/joyconfig.bat"]
     if steam_on: