Move outstanding work from TODO.md into the issue tracker

TODO.md carried two records in one file: what had been done, with the
measurements behind it, and what was left. The second half is what a tracker
is for, and keeping it here has already cost something -- AGENTS.md records a
round where eleven entries described code that had already changed, and this
file admitted to three more.

Every open item is now an issue on source.starfort.tech/andrew/libakgl,
labelled by kind and blast radius and milestoned by what it can land in: 0.9.x
for anything that breaks no ABI, 0.10.0 for new or changed public symbols,
1.0.0 for the design work. Four are epics: the performance plan (#60),
coverage (#61), actor rotation (#62), and the false header comments (#63).

Verified against the tree before filing rather than transcribed. Three entries
were already fixed and were not filed: the akgl_path_relative context leak, the
akgl_draw_background test extension, and the SDL enumeration audit -- keyboards,
gamepads and mappings are all freed in CLEANUP today. Two were reworded because
the code had moved: the fonts item is a missing teardown entry point rather than
a missing API, since akgl_text_unloadallfonts exists, and draw_world's tilemap
call is already bounded by numlayers, so only the per-layer actor rescan remains.

TODO.md keeps the part a tracker has no place for: why a decision went the way
it did, what the measurement was, and which arguments turned out to be wrong.

TODO.txt is deleted. Four of its eight entries had shipped -- actor-to-actor
collision, actor-to-world collision, automatic facing, image layers -- and the
four that had not are #74 through #77, with the GPU renderer's research links
kept because that is the part that took the time.

Every reference that named an item number or a moved section is repointed, in
the manual, the headers, the tests and the examples.

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

include/akgl/collision.h

@@ -74,7 +74,7 @@ struct akgl_CollisionWorld;
  *
  * Sub-stepping bounds how far an actor moves between collision tests, which
  * stops anything moving at ordinary speeds from passing through a wall. A
- * projectile is not moving at ordinary speeds. See `TODO.md`.
+ * projectile is not moving at ordinary speeds. See issue #56.
  */
 #define AKGL_COLLISION_FLAG_BULLET      0x00000008u
 
@@ -557,8 +557,8 @@ akerr_ErrorContext AKERR_NOIGNORE *akgl_collision_sync_actors(akgl_CollisionWorl
  * Follows the convention every pool here uses: akgl_heap_next_collision_proxy
  * finds a free slot and does **not** claim it, and this takes the reference.
  * Write the two adjacent, because until the reference is taken the slot is still
- * free and the next acquire hands out the same pointer. That is `TODO.md` "Known
- * and still open" item 8, it applies to four of the five existing pools, and
+ * free and the next acquire hands out the same pointer. That asymmetry is issue
+ * #14, it applies to four of the five existing pools, and
  * this one does not depart from it -- a sixth convention would be worse than the
  * defect.
  *

include/akgl/controller.h

@@ -231,7 +231,7 @@ akerr_ErrorContext AKERR_NOIGNORE *akgl_controller_handle_removed(void *appstate
  *
  * @warning A **negative** @p controlmapid is not rejected -- only the upper
  *          bound is checked -- and indexes before the start of
- *          ::akgl_controlmaps. TODO.md, "Known and still open" item 11.
+ *          ::akgl_controlmaps. TODO.md, "Defects".
  */
 akerr_ErrorContext AKERR_NOIGNORE *akgl_controller_pushmap(int controlmapid, akgl_Control *control);
 

include/akgl/error.h

@@ -51,7 +51,7 @@
 // AKERR_OUTOFBOUNDS on truncation instead. That is the better answer: the
 // compiler was right both times, and silencing it left the truncation
 // happening and unreported. Kept because they are public and a consumer may
-// have them; see TODO.md.
+// have them; see issue #20.
 #define DISABLE_GCC_WARNING_FORMAT_TRUNCATION			\
     _Pragma("GCC diagnostic push")				\
     _Pragma("GCC diagnostic ignored \"-Wformat-truncation\"")

include/akgl/game.h

@@ -217,7 +217,7 @@ void akgl_game_update_fps(void);
  *
  * @note This is a partial implementation: the name tables are written but the
  *       objects themselves are not, so the file is not yet enough to restore a
- *       session. See also TODO.md, "Known and still open" item 7 -- the writer
+ *       session. See also TODO.md, "Defects" -- the writer
  *       and the reader disagree on the name-field widths, so a save with any
  *       registered spritesheet cannot be read back.
  */

include/akgl/heap.h

@@ -22,8 +22,8 @@
  *          reference for you, and the other four do not -- their caller is
  *          expected to take it, which in practice the `*_initialize` function
  *          does. Until one is taken the slot is still free and the next
- *          allocation hands out the same pointer. TODO.md, "Known and still
- *          open" item 8.
+ *          allocation hands out the same pointer. Whether to make them symmetric
+ *          or document the split is issue #14.
  */
 
 #ifndef _AKGL_HEAP_H_

include/akgl/registry.h

@@ -23,7 +23,7 @@
  *          no-op akgl_set_property and an akgl_get_property that always hands
  *          back the caller's default, which in turn means akgl_render_2d_init
  *          and akgl_physics_init_arcade quietly ignore their configuration.
- *          TODO.md, "Known and still open" item 3.
+ *          TODO.md, "Formatting and hygiene".
  */
 
 #ifndef _AKGL_REGISTRY_H_
@@ -170,7 +170,7 @@ akerr_ErrorContext AKERR_NOIGNORE *akgl_registry_load_properties(char *fname);
  * @note The name table it reads disagrees with actor.h in two places: bits 11
  *       and 12 are named `UNDEFINED_11`/`UNDEFINED_12` rather than `MOVING_IN`
  *       and `MOVING_OUT`, so those two states cannot be named from JSON at all.
- *       TODO.md items 24-26.
+ *       TODO.md, "AKGL_ACTOR_STATE_STRING_NAMES".
  */
 akerr_ErrorContext AKERR_NOIGNORE *akgl_registry_init_actor_state_strings(void);
 /**

include/akgl/text.h

@@ -123,8 +123,9 @@ akerr_ErrorContext AKERR_NOIGNORE *akgl_text_unloadallfonts(void);
  * @note The empty string is **refused**, not drawn as nothing: SDL_ttf reports
  *       "Text has zero width" and this passes that on as `AKERR_NULLPOINTER`.
  *       akgl_text_measure() accepts it, so the two disagree. A caller drawing a
- *       line of text that may be empty has to check for it. TODO.md, "Known and
- *       still open".
+ *       line of text that may be empty has to check for it. Stale: the two agree
+ *       as of 0.5.0 -- an empty string returns success without rasterizing. See
+ *       TODO.md, "Found while rewriting the Doxygen comments", and issue #63.
  */
 akerr_ErrorContext AKERR_NOIGNORE *akgl_text_rendertextat(TTF_Font *font, char *text, SDL_Color color, int wraplength, int x, int y);
 /**

include/akgl/tilemap.h

@@ -484,7 +484,7 @@ akerr_ErrorContext AKERR_NOIGNORE *akgl_tilemap_load_tilesets(akgl_Tilemap *dest
  *          than `layers[i].texture`, so tileset textures are destroyed twice and
  *          image-layer textures never. Nothing is set to `NULL` either, so a
  *          second call is a use-after-free. It also does not release the actors
- *          the map's object layers created. TODO.md, "Known and still open"
+ *          the map's object layers created. TODO.md, "Defects"
  *          item 2.
  */
 akerr_ErrorContext AKERR_NOIGNORE *akgl_tilemap_release(akgl_Tilemap *dest);