feat(poc): rewind MCP, skill, and recover-ladder docs

Initial PoC: find_protection, tagged checkpoints, FLR, mutating catalog.
Lab 10.9 status enums (0=Initializing, 1=MeetingSLA). Credentials stay in gitignored config.json.

tests/test_recover.py

@@ -0,0 +1,12 @@
+from zerto_rewind_mcp.recover import download_token_from, session_id_from
+
+
+def test_session_id_shapes():
+    assert session_id_from("abc") == "abc"
+    assert session_id_from({"sessionId": "s1"}) == "s1"
+    assert session_id_from({"Identifier": "s2"}) == "s2"
+
+
+def test_download_token_shapes():
+    assert download_token_from("tok") == "tok"
+    assert download_token_from({"downloadToken": "t2"}) == "t2"