clear env, dont inherit nix wrapper env

src/main/java/com/gregor/jprototerm/ShellSession.java

@@ -27,6 +27,7 @@ public final class ShellSession implements AutoCloseable {
             Map<String, String> environment = new HashMap<>(System.getenv());
             environment.put("TERM", "xterm-kitty");
             environment.put("COLORTERM", "truecolor");
+            sanitizeWrapperEnvironment(environment);
             environment.putAll(envOverride);
 
             LinuxPty pty = LinuxPty.spawn(
@@ -42,6 +43,30 @@ public final class ShellSession implements AutoCloseable {
         }
     }
 
+    /**
+     * Strips the variables injected by the Nix launcher wrapper from the shell's
+     * environment so they do not leak into terminal subprocesses.
+     *
+     * <p>jprototerm is launched from a Nix wrapper that prepends Nix store paths to
+     * {@code LD_LIBRARY_PATH} (and adds a GL shim) so the bundled JavaFX/ghostty natives
+     * resolve. If the shell inherited that path, host programs run inside the terminal
+     * (e.g. {@code flatpak}, {@code pdftoppm}) would load the Nix copies of libraries such
+     * as freetype/fontconfig/glib, which in turn drag in the Nix glibc through their
+     * RUNPATHs and clash with the host {@code libc.so.6}. We restore the user's original
+     * {@code LD_LIBRARY_PATH}, captured by the wrapper before it prepended anything.
+     */
+    private static void sanitizeWrapperEnvironment(Map<String, String> environment) {
+        String hostLibraryPath = environment.remove("JPROTOTERM_HOST_LD_LIBRARY_PATH");
+        if (hostLibraryPath == null || hostLibraryPath.isEmpty()) {
+            environment.remove("LD_LIBRARY_PATH");
+        } else {
+            environment.put("LD_LIBRARY_PATH", hostLibraryPath);
+        }
+        // These are jprototerm's own runtime settings, not the user's shell environment.
+        environment.remove("GDK_BACKEND");
+        environment.remove("JLIBGHOSTTY_LIBRARY");
+    }
+
     public void startReading(TerminalPane pane) {
         reader.submit(() -> readOutput(pane));
     }