Also override libmagic for WDL files starting with import (PHP-130724)

WDL files without a version header that start with an import statement
are also misidentified as application/javascript by libmagic. Add a
catch-all rule for files starting with 'import "'. Reclassifying
JavaScript ES modules as text/plain is harmless.

Author: emmarogge

startupscript/post-startup.sh

@@ -94,12 +94,18 @@ if command -v rstudio-server &> /dev/null; then
 # WDL (Workflow Description Language) files - override JavaScript detection.
 # libmagic misidentifies WDL import statements as JavaScript/ES modules,
 # which causes RStudio to treat .wdl files as binary.
+# Rules for files starting with a version declaration:
 0 string version\ 1.0 Workflow Description Language source
 !:mime text/plain
 0 string version\ 1.1 Workflow Description Language source
 !:mime text/plain
 0 string version\ draft-2 Workflow Description Language source
 !:mime text/plain
+# Rule for files starting with an import (no version header).
+# This also matches JavaScript ES module files, but reclassifying them
+# as text/plain is harmless — they are still text.
+0 string import\ " Text source with imports
+!:mime text/plain
 MAGIC_EOF
 fi