refactor(P21): rename acdl_platform/ -> core/ (REQ-53)

---ci---
project: acdl
phase: 21
milestone: v1.6
status: execute
---/ci---

Rename the acdl_platform/ package to core/ across the directory, all
imports in tests/scripts/pipelines/workflows, and doc references. The
package is imported as core.confidence_signal / core.contract_resolver /
core.outbox_writer. The deploy workflow's platform-repo checkout dir is
renamed acdl-platform/ -> platform/ (workspace path, not the python
package). Both .gitea + .github workflows stay byte-identical.

Note: the original target name 'platform/' shadows Python's stdlib
platform module (pytest's import uuid -> platform.system() fails when
the repo root is on sys.path, which every test does). 'core/' avoids
the clash while honoring the intent (drop the verbose acdl_platform).

Tests: 154 pass. run_ci.sh green.

tests/test_confidence_signal.py

@@ -6,7 +6,7 @@ import pytest
 
 sys.path.insert(0, str(Path(__file__).resolve().parent.parent))
 
-from acdl_platform.confidence_signal import (
+from core.confidence_signal import (
     WEIGHTS, PENALTY, THRESHOLDS, compute, Signal, _per_input_score,
 )
 

tests/test_contract_resolver.py

@@ -25,7 +25,7 @@ class TestContractSchema:
 
 class TestResolveStaticAsset:
     def test_resolve_static_asset_contract(self, tmp_path):
-        from acdl_platform.contract_resolver import resolve
+        from core.contract_resolver import resolve
         stack = resolve(str(ROOT / "contracts/static-asset.yaml"), str(ROOT))
         assert stack["stack"]["name"] == "static-asset"
         assert stack["stack"]["kind"] == "l2"
@@ -33,7 +33,7 @@ class TestResolveStaticAsset:
         assert len(stack["resources"]) >= 1
 
     def test_resolve_static_asset_has_s3_resource(self):
-        from acdl_platform.contract_resolver import resolve
+        from core.contract_resolver import resolve
         stack = resolve(str(ROOT / "contracts/static-asset.yaml"), str(ROOT))
         s3_res = [r for r in stack["resources"] if r["type"] == "aws:s3:bucket"]
         assert len(s3_res) == 1
@@ -41,7 +41,7 @@ class TestResolveStaticAsset:
         assert s3_res[0]["inputs"]["region"] == "us-east-1"
 
     def test_resolve_static_asset_validates_against_stack_schema(self):
-        from acdl_platform.contract_resolver import resolve
+        from core.contract_resolver import resolve
         stack = resolve(str(ROOT / "contracts/static-asset.yaml"), str(ROOT))
         schema = json.load(open(ROOT / "schemas/stack.schema.json"))
         jsonschema.validate(stack, schema)
@@ -63,7 +63,7 @@ class TestResolveMicroservice:
         with open(contract_path, "w") as fh:
             yaml.dump(contract, fh)
         try:
-            from acdl_platform.contract_resolver import resolve
+            from core.contract_resolver import resolve
             stack = resolve(str(contract_path), str(ROOT))
             assert stack["stack"]["name"] == "microservice"
             assert stack["stack"]["kind"] == "l2"
@@ -86,7 +86,7 @@ class TestResolveL1Direct:
         contract_path = tmp_path / "test-s3.yaml"
         with open(contract_path, "w") as fh:
             yaml.dump(contract, fh)
-        from acdl_platform.contract_resolver import resolve
+        from core.contract_resolver import resolve
         stack = resolve(str(contract_path), str(ROOT))
         assert stack["stack"]["name"] == "s3"
         assert stack["stack"]["kind"] == "l1"
@@ -104,7 +104,7 @@ class TestResolveL1Direct:
         contract_path = tmp_path / "test-s3-schema.yaml"
         with open(contract_path, "w") as fh:
             yaml.dump(contract, fh)
-        from acdl_platform.contract_resolver import resolve
+        from core.contract_resolver import resolve
         stack = resolve(str(contract_path), str(ROOT))
         schema = json.load(open(ROOT / "schemas/stack.schema.json"))
         jsonschema.validate(stack, schema)
@@ -121,7 +121,7 @@ class TestResolveErrors:
         contract_path = tmp_path / "bad.yaml"
         with open(contract_path, "w") as fh:
             yaml.dump(contract, fh)
-        from acdl_platform.contract_resolver import resolve
+        from core.contract_resolver import resolve
         with pytest.raises(ValueError, match="not found in registry"):
             resolve(str(contract_path), str(ROOT))
 
@@ -130,7 +130,7 @@ class TestResolveErrors:
         contract_path = tmp_path / "incomplete.yaml"
         with open(contract_path, "w") as fh:
             yaml.dump(contract, fh)
-        from acdl_platform.contract_resolver import resolve
+        from core.contract_resolver import resolve
         with pytest.raises(jsonschema.ValidationError):
             resolve(str(contract_path), str(ROOT))
 

tests/test_outbox_writer.py

@@ -8,7 +8,7 @@ import pytest
 
 sys.path.insert(0, str(Path(__file__).resolve().parent.parent))
 
-from acdl_platform.outbox_writer import _canonical_hash, write_event
+from core.outbox_writer import _canonical_hash, write_event
 
 
 class TestCanonicalHash:

tests/test_pipeline.py

@@ -29,7 +29,7 @@ class TestPipelineIntegration:
 
     def test_confidence_signal_with_adapted_tf(self):
         sys.path.insert(0, str(ROOT))
-        from acdl_platform.confidence_signal import compute
+        from core.confidence_signal import compute
 
         inputs = {
             "policy": [{"result": "pass"}],

tests/test_pipeline_contract.py

@@ -78,7 +78,7 @@ class TestPipelineContract:
         contract = _load_yaml("pipelines/ci.yaml")
         lint = next(s for s in contract["stages"] if s["name"] == "lint")
         assert "py_compile" in lint["command"]
-        assert "acdl_platform/confidence_signal.py" in lint["command"]
+        assert "core/confidence_signal.py" in lint["command"]
         assert "adapters/terraform/adapter.py" in lint["command"]
 
     def test_contract_test_command_runs_pytest(self):
@@ -141,9 +141,9 @@ class TestWorkflowConformance:
         run_step = next(s for s in lint_job["steps"] if "run" in s)
         assert "py_compile" in run_step["run"]
         for py_file in [
-            "acdl_platform/confidence_signal.py",
-            "acdl_platform/outbox_writer.py",
-            "acdl_platform/contract_resolver.py",
+            "core/confidence_signal.py",
+            "core/outbox_writer.py",
+            "core/contract_resolver.py",
             "adapters/terraform/adapter.py",
             "adapters/terraform/policy/checkov_adapter.py",
             "scripts/push_consumer_image.py",
@@ -175,8 +175,8 @@ class TestRunCiScript:
     def test_run_ci_script_contains_lint_stage(self):
         content = open(ROOT / "scripts/run_ci.sh").read()
         assert "py_compile" in content
-        assert "acdl_platform/confidence_signal.py" in content
-        assert "acdl_platform/contract_resolver.py" in content
+        assert "core/confidence_signal.py" in content
+        assert "core/contract_resolver.py" in content
         assert "adapters/terraform/adapter.py" in content
 
     def test_run_ci_script_contains_test_stage(self):
@@ -198,9 +198,9 @@ class TestRunCiScript:
             ["bash", "-c",
              f"cd {ROOT} && "
              "python3 -m py_compile "
-             "acdl_platform/confidence_signal.py "
-             "acdl_platform/outbox_writer.py "
-             "acdl_platform/contract_resolver.py "
+             "core/confidence_signal.py "
+             "core/outbox_writer.py "
+             "core/contract_resolver.py "
              "adapters/terraform/adapter.py "
              "adapters/terraform/policy/checkov_adapter.py "
              "scripts/push_consumer_image.py && "
@@ -342,7 +342,7 @@ class TestDeployWorkflowConformance:
         deploy_job = wf["jobs"]["deploy"]
         platform_checkout = next(
             s for s in deploy_job["steps"]
-            if "checkout" in s.get("uses", "") and s.get("with", {}).get("path") == "acdl-platform"
+            if "checkout" in s.get("uses", "") and s.get("with", {}).get("path") == "platform"
         )
         assert platform_checkout["with"]["repository"] == "acdl/acdl"