Removes pins added while making the auto-default suite pass that weren't
actually testing older-protocol-only behavior, and keeps (with a stated
reason) the ones that are. Along the way, fixes two real defects the audit
surfaced in the modern protocol path: PingMiddleware could leak a
_active_sessions entry when a connection's exit_stack closed before its
keepalive task got its first scheduler turn, and FastMCP(experimental_
capabilities=...) was silently dropped from server/discover responses
(it only ever reached the legacy initialize handshake).
Client negotiates the newest mutual protocol era by default (probe
server/discover, fall back to the initialize handshake). ProxyClient and the
inspect utility explicitly pin the handshake era so proxy forwarding and
server_info reads are unchanged. SSE and multi-server config transports are
legacy-only. extensions= and result_claims= (SEP-2133) are thin passthroughs
to the SDK session.
Replaces the ___ separator for FastMCPApp backend tool routing with a
deterministic hash(app_name, tool_name) prefix, and replaces the shared
singleton prefab renderer resource with per-tool resources synthesized
on demand.
Backend tools are now callable via <hash>_<local_name> instead of
<app_name>___<local_name>. The dispatcher walks the provider tree
recursively via get_tool_by_hash (same pattern as get_app_tool).
Each prefab tool gets its own renderer resource at
ui://prefab/tool/<hash>/renderer.html with per-tool CSP — fixing the
bug where PrefabAppConfig(csp=...) never actually applied.
Closes#3735, closes#3805
* Rename ui= to app= and consolidate ToolUI/ResourceUI into AppConfig
* Remove backward-compat aliases for ToolUI/ResourceUI/ui_to_meta_dict
* Add extra=allow to AppConfig model_config for forward compatibility
