Add run-voyager, and make running depend on the disk

The jitter was a stale disk. An image built before the escape sequences came out still had
the old Snake on it, which sends ESC [ H every frame: the console swallows the escape,
because it is below the font's first character, and then draws "[H" as two ordinary letters.
So every frame began two characters to the right and one line further down than the last,
and the board walked down the screen. Not timing at all.

WHAT IS ON A DISK IS WHATEVER WAS BUILT WHEN THE DISK WAS MADE, and a machine whose console
has changed will start that image quite happily. That is the compatibility break we chose
when the parser came out, and it is fine - but it should not be a puzzle, so both run
targets depend on the disk rather than merely using it, and both READMEs say why.

run-voyager boots the same disk on the machine with a screen. It existed only as
EMU=../Voyager in front of run-cosmos, which is not a thing anybody should have to know.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01E2JrLzFvuFX9fgi1LDRjrW

Programs/makefile

@@ -69,6 +69,7 @@ run-%:
 #   make cosmos       Assemble the system and everything it can load.
 #   make cosmos-disk  ... and put the loadable programs on a disk image.
 #   make run-cosmos   ... and boot the machine with that disk in the drive.
+#   make run-voyager  ... and boot the machine that has a screen instead of a terminal.
 #
 # Programs in Apps/ say where they live with #Base, so the assembler writes them out as
 # loadable programs rather than as boot images. They are named .sbx to keep that
@@ -220,6 +221,22 @@ run-cosmos: $(COSMOS_DISK)
 run-cosmos-direct: $(COSMOS) $(COSMOS_DISK)
 	$(EMU) --disk $(COSMOS_DISK) $(COSMOS)
 
+# ---- The same disk, on the machine with a screen ----
+#
+# Voyager rather than SplitBit, which is the only difference: same disk, same system, same
+# programs, presented through a window instead of a terminal.
+#
+# IT DEPENDS ON THE DISK, and that matters more than it looks. What is on a disk is whatever
+# was built when the disk was made, so a machine whose console has changed will happily boot
+# an image full of programs written for the old one - and they will draw whatever the old
+# way now means. Making the disk a dependency of running it is what stops that being a
+# puzzle.
+run-voyager: $(COSMOS_DISK)
+	../Voyager --disk $(COSMOS_DISK)
+
+run-voyager-direct: $(COSMOS) $(COSMOS_DISK)
+	../Voyager --disk $(COSMOS_DISK) $(COSMOS)
+
 clean:
 	rm -rf $(BUILD)
 
@@ -227,4 +244,4 @@ clean:
 # reassembles every program that includes it.
 -include $(DEPENDENCIES)
 
-.PHONY: all clean cosmos cosmos-disk run-cosmos run-cosmos-direct
+.PHONY: all clean cosmos cosmos-disk run-cosmos run-cosmos-direct run-voyager run-voyager-direct