fix(cli): reject required positionals after optional ones

lib/bash/cli/lib_cli.sh

@@ -953,6 +953,7 @@ base_cli_option() {
 # Usage: base_cli_positional model command_path name [required=true] [repeatable=true] ...
 base_cli_positional() {
     local model="${1-}" path="${2-}" name="${3-}" key names
+    local previous previous_required
     local -a __base_bash_libs_cli_previous_positionals=()
 
     if (($# < 3)); then
@@ -991,12 +992,23 @@ base_cli_positional() {
     fi
     if [[ -n "$names" ]]; then
         IFS=, read -r -a __base_bash_libs_cli_previous_positionals <<< "$names"
-        local previous="${__base_bash_libs_cli_previous_positionals[${#__base_bash_libs_cli_previous_positionals[@]} - 1]}"
+        previous="${__base_bash_libs_cli_previous_positionals[${#__base_bash_libs_cli_previous_positionals[@]} - 1]}"
         if [[ "$(__base_bash_libs_cli_positional_meta__ "$model" "$path" "$previous" repeatable)" =~ ^(1|true|yes)$ ]]; then
             __base_bash_libs_cli_declaration_usage__ "base_cli_positional: cannot declare '$name' after repeatable positional '$previous'."
             return 2
         fi
     fi
+    if [[ "${__base_bash_libs_cli_attrs[required]-}" =~ ^(1|true|yes)$ && -n "$names" ]]; then
+        for previous in "${__base_bash_libs_cli_previous_positionals[@]}"; do
+            previous_required="$(__base_bash_libs_cli_positional_meta__ "$model" "$path" "$previous" required)"
+            if [[ ! "$previous_required" =~ ^(1|true|yes)$ ||
+                -n "${__base_bash_libs_cli_models["$model|positional|$path|meta|$previous|default"]+set}" ]]; then
+                __base_bash_libs_cli_declaration_usage__ \
+                    "base_cli_positional: cannot declare required positional '$name' after optional positional '$previous'."
+                return 2
+            fi
+        done
+    fi
     if [[ -n "$names" ]]; then names="$names,$name"; else names="$name"; fi
     __base_bash_libs_cli_models["$model|command|positionals|$path"]="$names"
     for key in help metavar default required enum validator repeatable; do

lib/bash/cli/tests/lib_cli.bats

@@ -296,6 +296,33 @@ EOF
     base_cli_parse optional_repeat -- run target-only
 }
 
+@test "required positionals cannot follow optional or defaulted positionals" {
+    base_cli_model_init ordering name=ordering
+    base_cli_command ordering run "Run"
+    base_cli_positional ordering run context
+
+    bats_run base_cli_positional ordering run target required=true
+    [ "$status" -eq 2 ]
+    [[ "$output" == *"cannot declare required positional 'target' after optional positional 'context'"* ]]
+    [ "${__base_bash_libs_cli_models[ordering\|command\|positionals\|run]}" = context ]
+
+    base_cli_model_init defaulted_order name=defaulted-order
+    base_cli_command defaulted_order run "Run"
+    base_cli_positional defaulted_order run context default=working
+
+    bats_run base_cli_positional defaulted_order run target required=true
+    [ "$status" -eq 2 ]
+    [[ "$output" == *"cannot declare required positional 'target' after optional positional 'context'"* ]]
+
+    base_cli_model_init valid_order name=valid-order
+    base_cli_command valid_order run "Run"
+    base_cli_positional valid_order run target required=true
+    base_cli_positional valid_order run context default=working
+    base_cli_parse valid_order -- run target-value
+    [ "${BASE_BASH_LIBS_CLI_RESULT_POSITIONALS[0]}" = target-value ]
+    [ "${BASE_BASH_LIBS_CLI_RESULT_POSITIONALS[1]}" = working ]
+}
+
 @test "quick declarations enforce required repeatable positional tails" {
     base_cli_declare table_repeat \
         'model|name=table-repeat' \