framework workflow tests: add inline user-defined tool case

Adds inline_user_defined_tool.gxwf.yml plus matching .gxwf-tests.yml to
lib/galaxy_test/workflow/. Workflow embeds the cat_user_defined UDT body
(matches test/functional/tools/cat_user_defined.yml) under a format2
run: block. Test job pipes inline content through the UDT and asserts
the output text.

Exercises end-to-end:
- gxformat2 _expand_format2 GalaxyUserToolStub pass-through (PR #218);
  without the fix _expand_format2 strips the stub to run=None and
  workflow import fails or silently drops the step
- Workflow import with embedded tool_representation
- On-import DynamicTool registration from the inline body
- YAML tool runtime execution in a container

The framework runner globs *.gxwf.yml and discovers the new pair via
pytest_generate_tests. Confirmed local: pytest collects
test_workflow[inline_user_defined_tool_0]; ensure_format2 +
ensure_native both preserve the GalaxyUserTool body; gxwf validate /
lint report the step as OK with only generic creator/license warnings.

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

lib/galaxy_test/workflow/inline_user_defined_tool.gxwf-tests.yml

@@ -0,0 +1,12 @@
+- doc: |
+    INLINE_UDT_BASIC: Cat through a single inline user-defined tool step.
+    Input file content round-trips to the workflow output unchanged.
+  job:
+    input1:
+      class: File
+      contents: "hello inline udt\n"
+  outputs:
+    wf_output:
+      asserts:
+        - that: has_text
+          text: "hello inline udt"

lib/galaxy_test/workflow/inline_user_defined_tool.gxwf.yml

@@ -0,0 +1,34 @@
+class: GalaxyWorkflow
+doc: |
+  Workflow with one inline user-defined tool (UDT) step. Exercises the
+  end-to-end path through Galaxy: format2 normalization (including
+  _expand_format2 pass-through for GalaxyUserToolStub, gxformat2 PR #218),
+  workflow import with tool_representation, on-import DynamicTool
+  registration, and execution via the YAML tool runtime.
+inputs:
+  input1:
+    type: data
+outputs:
+  wf_output:
+    outputSource: udt_cat/output1
+steps:
+  udt_cat:
+    run:
+      class: GalaxyUserTool
+      id: cat_user_defined
+      version: "0.1"
+      name: cat_user_defined
+      description: concatenates a file
+      container: busybox
+      shell_command: cat '$(inputs.input1.path)' > output.txt
+      inputs:
+        - name: input1
+          type: data
+          format: txt
+      outputs:
+        - name: output1
+          type: data
+          format: txt
+          from_work_dir: output.txt
+    in:
+      input1: input1