canary: detect provider API schema drift; release v0.7.0

The export reads ChatGPT's and Claude's undocumented internal web APIs,
which can change shape without notice; the worst failure for a backup tool
is a silent one (skipped/mis-parsed content with no error). Add a `canary`
command + BaseProvider.check_drift() (overridden by ChatGPT/Claude) that
fetches one listing page + one conversation per provider and asserts only
the normalizer's load-bearing fields — not the full response shape, which
churns harmlessly. The top silent risk it guards is a renamed retrieval-tool
author bypassing the hidden-content collapse. ERROR findings exit non-zero;
WARN findings are surfaced but non-fatal so a backup run is never blocked.

Also retires the in-app watch mode and headless StartOS direction from the
roadmap (tool stays a local, manually-run CLI) and updates docs.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

tests/test_providers.py

@@ -973,3 +973,146 @@ class TestChatGPTSessionHealth:
         ok, detail = p.session_health()
         assert ok is False
         assert "unreachable" in detail.lower()
+
+
+# ---------------------------------------------------------------------------
+# API-drift canary (§10): assert load-bearing fields, flag silent risks.
+# ---------------------------------------------------------------------------
+
+
+def _sev(findings):
+    return {f["severity"] for f in findings}
+
+
+def _checks(findings, severity):
+    return {f["check"] for f in findings if f["severity"] == severity}
+
+
+class TestChatGPTDriftCanary:
+    def _provider(self, page, detail):
+        from src.providers.chatgpt import ChatGPTProvider
+
+        p = ChatGPTProvider.__new__(ChatGPTProvider)
+        p.list_conversations = lambda offset=0, limit=5: page
+        p.get_conversation = lambda cid: detail
+        return p
+
+    @staticmethod
+    def _detail(mapping):
+        return {
+            "conversation_id": "c1", "title": "T",
+            "create_time": 1.0, "update_time": 2.0, "mapping": mapping,
+        }
+
+    @staticmethod
+    def _node(role="user", name=None, content_type="text", parts=("hello",)):
+        return {
+            "id": "n", "parent": None, "children": [],
+            "message": {
+                "author": {"role": role, "name": name},
+                "content": {"content_type": content_type, "parts": list(parts)},
+                "metadata": {},
+            },
+        }
+
+    def test_healthy_shape_is_ok_only(self):
+        from src.providers.base import DRIFT_OK
+
+        p = self._provider([{"id": "c1", "title": "T", "update_time": "x"}],
+                           self._detail({"n1": self._node()}))
+        assert _sev(p.check_drift()) == {DRIFT_OK}
+
+    def test_missing_listing_id_is_error(self):
+        from src.providers.base import DRIFT_ERROR
+
+        p = self._provider([{"title": "T"}], self._detail({"n1": self._node()}))
+        assert DRIFT_ERROR in _sev(p.check_drift())
+
+    def test_empty_mapping_is_error(self):
+        from src.providers.base import DRIFT_ERROR
+
+        p = self._provider([{"id": "c1", "title": "T", "update_time": "x"}],
+                           self._detail({}))
+        findings = p.check_drift()
+        assert "detail" in _checks(findings, DRIFT_ERROR)
+
+    def test_unfamiliar_tool_author_warns_collapse(self):
+        from src.providers.base import DRIFT_WARN
+
+        mapping = {
+            "n1": self._node(),  # a healthy text msg so parts check passes
+            "n2": self._node(role="tool", name="brand_new_retriever"),
+        }
+        p = self._provider([{"id": "c1", "title": "T", "update_time": "x"}],
+                           self._detail(mapping))
+        assert "collapse" in _checks(p.check_drift(), DRIFT_WARN)
+
+    def test_new_content_type_warns(self):
+        from src.providers.base import DRIFT_WARN
+
+        mapping = {
+            "n1": self._node(),
+            "n2": self._node(content_type="hologram_v2", parts=()),
+        }
+        p = self._provider([{"id": "c1", "title": "T", "update_time": "x"}],
+                           self._detail(mapping))
+        assert "content_type" in _checks(p.check_drift(), DRIFT_WARN)
+
+    def test_known_tool_author_not_flagged(self):
+        # file_search is a known collapse author — must NOT warn.
+        mapping = {
+            "n1": self._node(),
+            "n2": self._node(role="tool", name="file_search"),
+        }
+        p = self._provider([{"id": "c1", "title": "T", "update_time": "x"}],
+                           self._detail(mapping))
+        assert "collapse" not in _checks(p.check_drift(), "warn")
+
+
+class TestClaudeDriftCanary:
+    def _provider(self, page, detail):
+        from src.providers.claude import ClaudeProvider
+
+        p = ClaudeProvider.__new__(ClaudeProvider)
+        p.list_conversations = lambda offset=0, limit=5: page
+        p.get_conversation = lambda cid: detail
+        return p
+
+    @staticmethod
+    def _detail(msgs):
+        return {"uuid": "u1", "name": "N", "created_at": "x", "updated_at": "y",
+                "chat_messages": msgs}
+
+    def test_healthy_flat_shape_is_ok(self):
+        from src.providers.base import DRIFT_OK
+
+        msgs = [{"uuid": "m1", "sender": "human", "text": "hi",
+                 "created_at": "x", "attachments": [], "files": []}]
+        p = self._provider([{"uuid": "u1", "name": "N", "updated_at": "z"}],
+                           self._detail(msgs))
+        assert _sev(p.check_drift()) == {DRIFT_OK}
+
+    def test_content_as_list_warns(self):
+        from src.providers.base import DRIFT_WARN
+
+        msgs = [{"uuid": "m1", "sender": "assistant",
+                 "content": [{"type": "text", "text": "hi"}], "created_at": "x"}]
+        p = self._provider([{"uuid": "u1", "name": "N", "updated_at": "z"}],
+                           self._detail(msgs))
+        assert "content" in _checks(p.check_drift(), DRIFT_WARN)
+
+    def test_nonempty_attachments_warn(self):
+        from src.providers.base import DRIFT_WARN
+
+        msgs = [{"uuid": "m1", "sender": "human", "text": "hi",
+                 "created_at": "x", "attachments": [{"file_name": "a.pdf"}]}]
+        p = self._provider([{"uuid": "u1", "name": "N", "updated_at": "z"}],
+                           self._detail(msgs))
+        assert "attachments" in _checks(p.check_drift(), DRIFT_WARN)
+
+    def test_empty_messages_is_error(self):
+        from src.providers.base import DRIFT_ERROR
+
+        p = self._provider([{"uuid": "u1", "name": "N", "updated_at": "z"}],
+                           self._detail([]))
+        assert DRIFT_ERROR in _sev(p.check_drift())