sud: fail fast on malformed sud.json documents, one test per fixture

Sud.load() now calls utils/sud_validate.py's validate_sud() before
parsing: requires a non-empty 'steps' list, and for every resolved
step that sets its own 'temperature', a numeric ramp.rate - the one
genuinely unguarded crash site (ramp['rate'], no .get() fallback) hit
in tasks/sud.py, components/sud_forecast.py and demo_sud.py the moment
that step is reached, which for SudForecastEstimator can be as early
as the Load itself. A refused load is now logged with the specific
reason (previously silent). validate_sud() reuses Sud._parse_data()
directly rather than reimplementing default-merging/step-building.

tests/utils/test_sud_validate_fixtures.py covers 8 fixture docs plus
all 6 real sude/*.json files; tests/components/sud/test_sud_load.py
exercises the Sud.load() wiring itself (rejects, keeps prior schedule).

Also reworked both this and test_config_fixtures.py to generate one
dedicated test method per fixture file (dynamic setattr) instead of
looping with subTest inside a single method - subTest iterations don't
show up individually in `unittest -v`/IDE test runners, which made it
look like far fewer fixtures were covered than actually are.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01F4oEE99rkKVU8L8tkzXWdG

tests/utils/test_sud_validate_fixtures.py

@@ -0,0 +1,79 @@
+import json
+import os
+import re
+import unittest
+
+from utils.config_validate import ConfigError
+from utils.sud_validate import validate_sud
+
+FIXTURES_DIR = os.path.join(os.path.dirname(__file__), 'sud_fixtures')
+SUDE_DIR = os.path.join(os.path.dirname(__file__), '..', '..', 'sude')
+
+# filename -> None if the fixture should pass validation, otherwise a regex
+# matched against the raised ConfigError's message.
+CASES = {
+    'valid_minimal.json': None,
+    'valid_with_target.json': None,
+    'valid_multi_step.json': None,
+    'missing_steps_key.json': r"missing required config key: steps",
+    'empty_steps_list.json': r"'steps' must be a non-empty list",
+    'missing_ramp_rate.json': r'step 1 \(Heat up\): .*ramp\.rate',
+    'ramp_rate_wrong_type.json': r'step 1 \(Heat up\): .*ramp\.rate',
+    'step_not_dict.json': r'malformed sud document',
+}
+
+
+def _load(directory, name):
+    with open(os.path.join(directory, name)) as f:
+        return json.load(f)
+
+
+def _test_name(filename):
+    return 'test_' + re.sub(r'\W', '_', filename[:-len('.json')])
+
+
+class TestSudValidateFixtures(unittest.TestCase):
+    def test_every_fixture_file_is_covered(self):
+        on_disk = {f for f in os.listdir(FIXTURES_DIR) if f.endswith('.json')}
+        self.assertEqual(on_disk, set(CASES), "sud_fixtures/ and CASES have drifted apart")
+
+
+def _make_fixture_test(name, expected_error):
+    def test(self):
+        data = _load(FIXTURES_DIR, name)
+        if expected_error is None:
+            validate_sud(data)  # must not raise
+        else:
+            with self.assertRaisesRegex(ConfigError, expected_error):
+                validate_sud(data)
+    return test
+
+
+# One dedicated test method per fixture file - not a single method looping
+# over CASES with subTest - so `unittest discover -v` (and any IDE test
+# runner) lists and can re-run each fixture individually instead of folding
+# them all into one opaque "did any of these fail" result.
+for _name, _expected_error in CASES.items():
+    setattr(TestSudValidateFixtures, _test_name(_name), _make_fixture_test(_name, _expected_error))
+
+
+class TestRealSudFiles(unittest.TestCase):
+    """The actual sude/*.json schedules must always pass - a failure here
+    means either a real schedule is broken, or validate_sud() itself has
+    drifted from what Sud._parse_data() actually accepts."""
+
+
+def _make_real_file_test(name):
+    def test(self):
+        validate_sud(_load(SUDE_DIR, name))
+    return test
+
+
+_real_sud_files = [f for f in os.listdir(SUDE_DIR) if f.endswith('.json')]
+assert _real_sud_files, "expected at least one sude/*.json file"
+for _name in _real_sud_files:
+    setattr(TestRealSudFiles, _test_name(_name), _make_real_file_test(_name))
+
+
+if __name__ == '__main__':
+    unittest.main()