feat(context): Decouple context composition from files and media

tests/test_context_composition_decoupled.py

@@ -0,0 +1,47 @@
+import pytest
+from src.app_controller import AppController
+from src.models import FileItem
+
+def test_context_files_is_decoupled():
+    controller = AppController()
+    
+    # Verify both lists exist and are distinct
+    assert hasattr(controller, 'files')
+    assert hasattr(controller, 'context_files')
+    assert controller.files is not controller.context_files
+    
+    # Modifying one should not affect the other
+    controller.files.append(FileItem(path="whitelist.txt"))
+    controller.context_files.append(FileItem(path="context.txt"))
+    
+    assert len(controller.files) == 1
+    assert controller.files[0].path == "whitelist.txt"
+    
+    assert len(controller.context_files) == 1
+    assert controller.context_files[0].path == "context.txt"
+
+def test_do_generate_uses_context_files(monkeypatch):
+    controller = AppController()
+    controller.init_state()
+    controller.context_files = [FileItem(path="context.txt")]
+    controller.files = [FileItem(path="whitelist.txt")]
+    
+    # Mock project_manager.flat_config and aggregate.run to verify passed data
+    import src.project_manager as pm
+    import src.aggregate as agg
+    
+    def mock_flat_config(*args, **kwargs):
+        return {"files": {}}
+    
+    def mock_aggregate_run(flat, **kwargs):
+        assert flat["files"]["paths"] == controller.context_files
+        return ("md", "path", [], "stable_md", "disc_text")
+        
+    monkeypatch.setattr(pm, "flat_config", mock_flat_config)
+    monkeypatch.setattr(pm, "save_project", lambda *args: None)
+    monkeypatch.setattr(agg, "run", mock_aggregate_run)
+    monkeypatch.setattr(agg, "build_markdown_no_history", lambda *args, **kwargs: "stable")
+    monkeypatch.setattr(agg, "build_discussion_text", lambda *args, **kwargs: "disc")
+    
+    # Should not raise assertion error
+    controller._do_generate()