Tighten requirements-catalog divergence notes to match current SDK behaviour

- resources:annotations: drop the stale lastModified divergence; the model
  now carries the field and it round-trips.
- lifecycle:capability:client-not-declared: narrow to the one remaining gap
  (the deprecated send_roots_list_changed path); the handler half is correct
  by construction.
- lifecycle:pre-initialization-ordering: mark removed_in=2026-07-28; the
  initialize handshake is gone in the new spec.
- client-transport:http:session-404-reinitialize: reword as an intentional
  cross-SDK choice (404 surfaced to caller), not a missed MUST.
- test_resources: drop the now-redundant lastModified xfail.

Author: maxisbey

tests/interaction/_requirements.py

@@ -178,13 +178,15 @@ def __post_init__(self) -> None:
         ),
         divergence=Divergence(
             note=(
-                "The client does not check its own declared capabilities before sending notifications or "
-                "serving callbacks; nothing prevents a caller from violating the spec's MUST."
+                "The handler half is correct by construction -- the client derives its declared "
+                "capabilities from the callbacks registered at construction, so it cannot serve a "
+                "capability it did not declare. Only the deprecated send_roots_list_changed notification "
+                "is ungated: a caller can send it without having registered a roots callback."
             ),
         ),
         deferred=(
-            "Not implemented in the SDK: the client does not check its own declared capabilities before "
-            "sending notifications or serving callbacks."
+            "Not implemented in the SDK: the deprecated send_roots_list_changed notification is not "
+            "gated on a declared roots capability."
         ),
     ),
     "lifecycle:capability:server-not-advertised": Requirement(
@@ -300,6 +302,8 @@ def __post_init__(self) -> None:
             "Before initialization completes, the client sends no requests other than pings, and the "
             "server sends no requests other than pings and logging."
         ),
+        removed_in="2026-07-28",
+        note="initialize handshake removed at 2026-07-28; per-request _meta envelope replaces it.",
         divergence=Divergence(
             note=(
                 "The server's send methods (create_message / elicit_form / list_roots) do not check "
@@ -1071,12 +1075,6 @@ def __post_init__(self) -> None:
     "resources:annotations": Requirement(
         source=f"{SPEC_BASE_URL}/server/resources#annotations",
         behavior="Resource annotations supplied by the server round-trip to the client in the list result.",
-        divergence=Divergence(
-            note=(
-                "The SDK Annotations model is missing the schema's lastModified field; MCPModel uses the "
-                "pydantic default extra='ignore', so the value is silently dropped on parse."
-            ),
-        ),
     ),
     "resources:capability:declared": Requirement(
         source=f"{SPEC_BASE_URL}/server/resources#capabilities",
@@ -3163,8 +3161,9 @@ def __post_init__(self) -> None:
         transports=("streamable-http",),
         divergence=Divergence(
             note=(
-                "The client surfaces the 404 as an error to the caller instead of re-initializing a new "
-                "session; the spec's MUST is not satisfied."
+                "The 404 is intentionally surfaced to the caller; this matches the TypeScript, C#, and "
+                "Go SDKs. The 2025-11-25 MUST was removed in the 2026 spec (SEP-2567), and the transport "
+                "layer cannot safely re-initialize without replaying the caller's request."
             ),
         ),
         deferred=(

tests/interaction/lowlevel/test_resources.py

@@ -39,10 +39,8 @@
 async def test_list_resources_returns_registered_resources(connect: Connect) -> None:
     """Listed resources reach the client with their URIs, names, and optional descriptive fields intact.
 
-    The fully-populated entry includes annotations, so the snapshot also proves they round-trip.
-    The SDK's Annotations model omits the schema's lastModified field (see the divergence on
-    resources:annotations); the input is built via model_validate with lastModified set so the
-    snapshot pins the drop and will fail once the SDK adds the field.
+    The fully-populated entry includes annotations (audience, priority, last_modified), so the
+    snapshot also proves they round-trip.
     """
 
     async def list_resources(