Move outstanding work from TODO.md into the issue tracker

Twenty-six issues on source.starfort.tech/andrew/akbasic, labelled by kind and
blast radius and milestoned by what they can land in: 0.1.x for anything that
changes no public contract, 0.2.0 for new verbs and observable behaviour
changes, 1.0.0 for the design decisions. Everything carries status::grooming.

Block surgery rather than a rewrite. Every open item is replaced by a line
saying what it was and which issue carries it; everything else -- the settled
design decisions, the deviation register, the fixed defects and the reasoning
behind the measurements -- is byte-identical. 3338 lines to 2966.

Two corrections found while doing it. The "what remains, in priority order"
list named groups A, D, F, J and H as outstanding language work; SS4's own table
shows every one of them done, and what actually survives is one piece of
structural work that is not a verb -- block skipping by source line, which is
why a whole FOR/NEXT on one line never loops. And the two UI gaps SS7 recorded
and declined to file are now libakgl #79 and #80: that section's rule is right
that changing a dependency is that repository's decision, and it does not
follow that reporting the gap is.

Cross-repository references to deps/*/TODO.md sections are repointed at the
trackers that now hold them, here and in MAINTENANCE.md.

Verified: cmake --build build && ctest --test-dir build, 112/112.

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

MAINTENANCE.md

@@ -201,7 +201,7 @@ compile-time test `libakstdlib` could not write against `libakerror` — and `ak
 floor is enforced instead by an `#error` feature-testing `AKERR_FIRST_CONSUMER_STATUS`, which
 `akstdlib.h`, `akgl/error.h` and our own `include/akbasic/error.h` all carry — include any of
 them and you inherit the guard. The missing version file is filed in
-`deps/libakstdlib/TODO.md` §2.3; when it lands, add the `1.0` floor to the `find_dependency`
+`libakstdlib` issue #5 and `libakerror` issue #16; when it lands, add the `1.0` floor to the `find_dependency`
 calls.
 
 ### Embedding all three dependencies collides four ways
@@ -253,7 +253,7 @@ target with the same name already exists"*. We shadow `add_custom_target` and re
 to `akerror_coverage` on the way past. `libakstdlib` (both targets) and `libakgl` (its
 `mutation` target) namespace themselves correctly. **The real fix is upstream in
 `libakerror`** — the same `CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR` test it already
-applies to `mutation` — and it is filed in `deps/libakstdlib/TODO.md` §2.3. Delete the
+applies to `mutation` — and it is filed as `libakerror` issue #15. Delete the
 workaround when it lands.
 
 **4. Stale build trees poison the coverage report.** See below; it is the reason for