Refresh the interaction manifest after main's notification-POST and output-schema changes

Drop the deferred hosting:http:modern:notification-post entry: the modern HTTP
entry now takes the spec's accept branch (202, not dispatched) and main ships its
own tested entry, hosting:http:modern:notification-post-202, for the same
streamable-http sentence, so the branch's undecided-design deferral is superseded.

Rewrite the client:jsonschema:ref-resolution:no-network-fetch deferral: the
client now validates output schemas against an explicitly empty reference
registry, so an external $ref is never fetched and a result reaching one fails
with the SDK's 'Invalid schema for tool <name>' error. The premise that no
behaviour exists to pin is false; the entry becomes a not-yet-covered flip
candidate describing the test to write.

Tighten the two 2025:jsonschema:ref-rewrite deferrals: the output-schema
generator now inlines a self-referential model's bare root $ref into an object
root, so 'no code rewrites schema documents' was imprecise. No pointer is ever
re-targeted, which is the substance both entries defer on.

Author: maxisbey

tests/interaction/_requirements.py

@@ -1595,11 +1595,13 @@ def __post_init__(self) -> None:
         ),
         added_in="2026-07-28",
         deferred=(
-            "Untestable negative through the public API: proving the validator never performs a network "
-            "fetch is a universally-quantified negative this suite refuses -- the client hands the "
-            "advertised outputSchema to the jsonschema library with no custom resolver "
-            "(src/mcp/client/session.py), and no public knob configures network retrieval whose absence "
-            "a test could pin."
+            "Not yet covered here: the client compiles each advertised outputSchema against an explicitly "
+            "empty reference registry (src/mcp/client/session.py), so a $ref naming a URI outside the schema "
+            "document is never retrieved, and a result whose validation reaches one fails with the "
+            "SDK-authored 'Invalid schema for tool <name>' error instead of passing; "
+            "tests/client/test_output_schema_validation.py pins that rejection with a file URI. The test "
+            "here advertises an outputSchema whose property $ref names an https URI from a low-level Server "
+            "and asserts call_tool raises that error."
         ),
     ),
     "client:jsonschema:unsupported-dialect-graceful": Requirement(
@@ -1808,10 +1810,12 @@ def __post_init__(self) -> None:
             "Era-bound: 2025-era-only legacy interop projection (see 2025:jsonschema:non-object-output-wrapped's note)."
         ),
         deferred=(
-            "Not implemented in the SDK: no $ref rewriting exists anywhere in src/mcp/server/ -- "
-            "schemas are generated whole from pydantic models with $defs at the document root "
-            "(src/mcp/server/mcpserver/utilities/func_metadata.py), and the SEP-2106 wrap-then-rewrite "
-            "projection that would create dangling pointers does not exist."
+            "Not implemented in the SDK: no $ref pointer is ever re-targeted anywhere in src/mcp/server/ -- "
+            "schemas are generated whole from pydantic models with $defs at the document root, and the one "
+            "schema edit the generator makes (inlining a self-referential return model's bare root $ref into "
+            "an object root, src/mcp/server/mcpserver/utilities/func_metadata.py) leaves every pointer into "
+            "$defs intact; the SEP-2106 wrap-then-rewrite projection that would create dangling pointers "
+            "does not exist."
         ),
     ),
     "2025:jsonschema:ref-rewrite-scope": Requirement(
@@ -1827,8 +1831,8 @@ def __post_init__(self) -> None:
         ),
         deferred=(
             "Not implemented in the SDK: the rewrite whose scoping this entry refines does not exist "
-            "(see 2025:jsonschema:ref-rewrite-on-wrap); no code in src/mcp/server/ walks or rewrites "
-            "schema documents."
+            "(see 2025:jsonschema:ref-rewrite-on-wrap); no code in src/mcp/server/ walks a schema "
+            "document or re-targets its $ref or $dynamicRef pointers."
         ),
     ),
     "2025:jsonschema:schemaless-non-object-sc-wrapped": Requirement(
@@ -6265,26 +6269,6 @@ def __post_init__(self) -> None:
             "proposal, not yet a manifest entry)."
         ),
     ),
-    "hosting:http:modern:notification-post": Requirement(
-        source=f"{SPEC_2026_BASE_URL}/basic/transports/streamable-http#sending-messages",
-        behavior=(
-            "A POST to the modern entry whose body is a notification (no id) is acknowledged without a "
-            "JSON-RPC response: 202 Accepted with an empty body, or the explicit cannot-accept "
-            "rejection -- the transport's two sanctioned responses."
-        ),
-        added_in="2026-07-28",
-        transports=("streamable-http",),
-        deferred=(
-            "Not yet covered here: which sanctioned response the modern entry gives is an explicitly "
-            "unmade design choice -- the cannot-accept branch it takes today carries the in-code TODO "
-            "recording strict-vs-lenient as open (src/mcp/server/_streamable_http_modern.py) -- so "
-            "pinning the current rejection would manufacture churn when the choice lands."
-        ),
-        note=(
-            "Only observable over streamable HTTP. The legacy path's 202 for notification POSTs is "
-            "pinned by hosting:http:notifications-202."
-        ),
-    ),
     "hosting:http:modern-only:initialize-rejection-names-versions": Requirement(
         source="sdk",
         behavior=(