Merge branch 'fix/arrows-http-backspace': held arrow keys, ludic build Http.* link, macOS Backspace

# Conflicts:
#	tools/ludic-cli/build.ludic

changes/arrow-keys.md

@@ -0,0 +1,9 @@
+bump: patch
+type: fix
+**Held arrow keys register** — `Key.Up`, `Key.Down`, `Key.Left` and `Key.Right` are 128-131.
+
+They folded to the codes of w, s, a and d, which is what the single per-frame key
+(`Input.key`) reports for an arrow. The held-key set has always stored an arrow under
+128-131, so `Input.key_down(Key.Up)` tested the W bit and `Input.move_i`'s arrow half never
+moved anything. `Input.key` keeps its WASD alias: a game comparing it with `'w'` still
+takes the arrows.

changes/backspace-key.md

@@ -0,0 +1,7 @@
+bump: patch
+type: fix
+**Backspace fires on macOS** — the Delete key reports `Key.Backspace` (8).
+
+AppKit gives the key marked delete (kVK_Delete, 51) the character `NSDeleteCharacter`, 127,
+which is what both the held-key set and the per-frame key received, so `Key.Backspace` never
+matched. `cocoa.ll` maps key code 51 to 8 in both.

changes/ludic-build-http.md

@@ -0,0 +1,8 @@
+bump: patch
+type: fix
+**`ludic build` links `Http.*`** — a program that uses the HTTP client builds through the CLI.
+
+`compile_app` linked the OpenGL backend when a program named `@lgl_*` but never
+`runtime/native/http.ll` and Foundation for `@hs_*`, so a `Http.*` program failed to link
+under `ludic build` / `ludic run` while `ludicc -o` built it. It now links them the same way,
+windowed and headless.