Break shows registers it chose, not ones it inherited

Break left DP1 and DP2 alone, so what a stop printed for them was whatever the
shell happened to have left there - which is a CosmOS address, which moves
whenever CosmOS is touched at all. The recorded output had to be taken again
four times in one day's work, every time for a value that is not this program's
and that nothing should ever depend on.

It sets all three of the pointers it owns now, rotated between the two stops so
that every one of them visibly changes, the way A and B already did. DP3 stays
as the system left it: it is where the program was entered, which is the one
thing worth seeing here that this program did not choose, and it is steady
because it is this program's own base.

A demonstration of what the registers were should show registers somebody
chose. Then every line of the record is being asserted rather than merely
observed, and a reader can tell which is which.

Checked both ways: sixty four bytes added to CosmOS's data no longer moves it,
and reading the frame at the wrong offset still fails it.

cosmosRun and cosmosMonitor move because Break is sixteen bytes longer and both
of them list the disk it sits on.

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

Tests/manifest

@@ -285,7 +285,12 @@ cosmosSay            | CosmOS/Source/cosmos.asm           | run      | cosmosSay
 # design and one that overwrites an instruction, since an overwritten instruction has to be
 # put back to continue and putting it back is the same act as disarming the breakpoint.
 # Every value shown comes out of the interrupt frame rather than the registers, because by
-# the time the handler runs the registers are the handler's.
+# the time the handler runs the registers are the handler's. Break sets all three of the
+# pointers it owns and rotates them between the two stops, so every value recorded here is
+# one something chose - it used to leave two of them holding whatever the shell had left,
+# which tied this record to where CosmOS's code sits and made it churn on changes that had
+# nothing to do with breakpoints. DP3 is left as the system set it, being where the program
+# was entered.
 cosmosBreak          | CosmOS/Source/cosmos.asm           | run      | cosmosBreak.in     | -     | disks/cosmos.img
 # The editor, which is the first program on this machine that makes a file a person typed:
 # every byte on every other image here was put there by the host tool. It is run twice in