fix: restore green builds and align frontend-backend contracts (P0)

- Isolate Settings tests from .env and process env leakage
- Fix analytics metadata test to unwrap psycopg Json wrapper
- Remove unused state variables causing frontend build failures
- Fix ReviewPage to use /classifications endpoint instead of nonexistent /result
- Normalize ReviewPage status enums (failed not error) and access_type values
- Align api.ts types with backend response shapes (ReplayPage, AnalyticsData, AgentUsage)

backend/tests/unit/analytics/test_event_recorder.py

@@ -145,4 +145,11 @@ class TestPostgresAnalyticsRecorder:
         )
         call_args = mock_conn.execute.call_args
         params = call_args[0][1]
-        assert params["metadata"] == {"key": "val"}
+        # PostgresAnalyticsRecorder wraps metadata with psycopg Json() adapter.
+        # Unwrap to compare the inner dict.
+        from psycopg.types.json import Json
+
+        meta = params["metadata"]
+        if isinstance(meta, Json):
+            meta = meta.obj
+        assert meta == {"key": "val"}

backend/tests/unit/test_config.py

@@ -7,10 +7,41 @@ import pytest
 from app.config import Settings
 
 
+def _isolated_settings(**kwargs: object) -> Settings:
+    """Create a Settings instance that ignores .env files and process env vars.
+
+    pydantic-settings reads from env_file and environment by default, which
+    causes test results to depend on the machine they run on.  We override
+    model_config at the class level temporarily so that every test gets
+    deterministic results.
+    """
+    # Build a throwaway subclass that disables env-file and env-var loading.
+    class _IsolatedSettings(Settings):
+        model_config = Settings.model_config.copy()
+        model_config["env_file"] = None  # type: ignore[assignment]
+        model_config["env_ignore_empty"] = True
+
+    # _env_parse_none_str makes pydantic-settings treat missing env vars as
+    # absent rather than empty-string, so required fields will raise.
+    import os
+
+    env_backup = os.environ.copy()
+    # Strip all env vars that Settings knows about so they can't leak in.
+    settings_fields = set(Settings.model_fields)
+    for key in list(os.environ):
+        if key.lower() in settings_fields:
+            del os.environ[key]
+    try:
+        return _IsolatedSettings(**kwargs)  # type: ignore[return-value]
+    finally:
+        os.environ.clear()
+        os.environ.update(env_backup)
+
+
 @pytest.mark.unit
 class TestSettings:
     def test_default_values(self) -> None:
-        settings = Settings(
+        settings = _isolated_settings(
             database_url="postgresql://x:x@localhost/db",
             anthropic_api_key="key",
         )
@@ -20,7 +51,7 @@ class TestSettings:
         assert settings.interrupt_ttl_minutes == 30
 
     def test_custom_values(self) -> None:
-        settings = Settings(
+        settings = _isolated_settings(
             database_url="postgresql://x:x@localhost/db",
             llm_provider="openai",
             llm_model="gpt-4o",
@@ -33,18 +64,18 @@ class TestSettings:
 
     def test_invalid_provider_rejected(self) -> None:
         with pytest.raises(Exception):
-            Settings(
+            _isolated_settings(
                 database_url="postgresql://x:x@localhost/db",
                 llm_provider="invalid",
             )
 
     def test_missing_database_url_rejected(self) -> None:
         with pytest.raises(Exception):
-            Settings(anthropic_api_key="key")
+            _isolated_settings(anthropic_api_key="key")
 
     def test_empty_api_key_for_provider_rejected(self) -> None:
         with pytest.raises(ValueError, match="API key"):
-            Settings(
+            _isolated_settings(
                 database_url="postgresql://x:x@localhost/db",
                 llm_provider="anthropic",
                 anthropic_api_key="",
@@ -52,7 +83,7 @@ class TestSettings:
 
     def test_wrong_provider_key_rejected(self) -> None:
         with pytest.raises(ValueError, match="API key"):
-            Settings(
+            _isolated_settings(
                 database_url="postgresql://x:x@localhost/db",
                 llm_provider="openai",
                 anthropic_api_key="key",