Cart injection: use the literal language name "Pico-8 Lua"

Zed resolves `injection.language` by matching it against the target
language's `name` field ( config.toml ) via UniCase, which folds case
but does NOT treat `-` as equivalent to ` `. The previous string
"pico-8-lua" therefore did not resolve to any registered language and
the entire __lua__ section rendered with zero highlights inside Zed.

Per `LanguageRegistry::language_for_name_or_extension` in
crates/language/src/language_registry.rs, only the `name` field and
`path_suffixes` are consulted — the directory under languages/, the
grammar `name`, the `scope`, and the tree-sitter.json `injection-regex`
field are all ignored. ( `injection-regex` is a Helix/Neovim
convention; Zed's production code never reads it. )

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

languages/pico-8-cart/injections.scm

@@ -1,5 +1,10 @@
 ; Hand the body of the __lua__ section to the Pico-8 Lua grammar so the
 ; dialect-aware parser parses it (compound-assignment statements, the `?`
 ; print shorthand, single-line `if (cond) stmt`, peek prefixes, etc.).
+;
+; The injection.language string must match the target language's `name`
+; field in its config.toml. Zed case-folds via UniCase but does not
+; treat hyphens as equivalent to spaces, so this has to be the literal
+; "Pico-8 Lua" ( with a space ).
 ((lua_content) @injection.content
- (#set! injection.language "pico-8-lua"))
+ (#set! injection.language "Pico-8 Lua"))