Fix input preview hash -> cid key mismatch

Template uses inp.cid and input.cid but router created previews with
'hash' key. Fixed both input_previews and run_inputs to use 'cid'.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

tests/test_run_artifacts.py

@@ -36,6 +36,33 @@ class TestCacheNotFoundTemplate:
             "Route should pass cid=cid to not_found.html template"
 
 
+class TestInputPreviewsDataStructure:
+    """Tests for input_previews dict keys matching template expectations."""
+
+    def test_run_card_template_expects_inp_cid(self) -> None:
+        """Run card template uses inp.cid for input previews."""
+        path = Path('/home/giles/art/art-celery/app/templates/runs/_run_card.html')
+        content = path.read_text()
+
+        assert 'inp.cid' in content, \
+            "Run card template should use inp.cid for input previews"
+
+    def test_input_previews_use_cid_key(self) -> None:
+        """
+        Regression test: input_previews must use 'cid' key not 'hash'.
+
+        Bug: Router created input_previews with 'hash' key but template expected 'cid'.
+        """
+        path = Path('/home/giles/art/art-celery/app/routers/runs.py')
+        content = path.read_text()
+
+        # Should have: "cid": input_hash, not "hash": input_hash
+        assert '"cid": input_hash' in content, \
+            "input_previews should use 'cid' key"
+        assert '"hash": input_hash' not in content, \
+            "input_previews should not use 'hash' key (template expects 'cid')"
+
+
 class TestArtifactDataStructure:
     """Tests for artifact dict keys matching template expectations."""