Move the CosmOS third of the Programming Manual to CosmOS

386 of the manual's 1,116 lines documented an operating system rather than
a machine. The split inside that file was never tutorial against reference;
it was the machine against the software that happens to run on it.

  What A Program May Ask The System For   129  -> CosmOS README
  Programs That Come With The System       111  -> CosmOS README
  Reading And Writing The Filesystem        64  -> CosmOS README
  Loading A Program From A Disk             52  -> Assembler Manual
  The Console Library                       25  -> CosmOS README

The services are the clearest case: a hundred and thirty lines describing
what CosmOS offers a program, in the manual for a CPU that has no operating
system of its own. A different system on the same machine would offer
different services and that section would be wrong for it.

The loadable program format goes to the Assembler Manual instead, because
SBEX is a thing the assembler WRITES. Nothing in the CPU knows what it is.

The Programming Manual is 716 lines and fourteen sections now, all of them
about the machine.

TWO DUPLICATE DESCRIPTIONS COLLAPSED INTO ONE EACH. The application list
existed in both documents in different words, and the CosmOS copy had gone
stale - no Break, no Stream, no assembler - because only the manual's copy
was checked. Moving the checked one in and deleting the other leaves one
list, and docs.sh follows it.

The second was made by this commit and caught while reading the seams: the
CosmOS README already had a service table, so the move briefly produced two.
That section now says what services are for and points at the one table.

Renaming a section as it moved: "Reading And Writing The Filesystem" is
"The Filesystem Library", which says what it is and reads beside "The
Console Library".

docs.sh follows all five, and each was verified by renaming the heading in
its new home and reading the complaint. The README and the CosmOS README
both described what the other manuals cover, and both were wrong the moment
this landed; they say the division out loud now, since it is the point.

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

.gitignore

@@ -23,3 +23,6 @@ __pycache__/
 *.bin
 *.sbx
 *.img
+
+# Kate leaves these beside a file it has open.
+.*.kate-swp