raise without from discards exception chain in 12 remaining sites

Initial Checks

• I confirm that I'm using the latest version of MCP Python SDK
• I confirm that I searched for my issue in https://github.com/modelcontextprotocol/python-sdk/issues before opening this issue

Description

Follow-up to #2541 (fixed in #2542). The same pattern exists in 12 additional sites across 7 files. Each catches an exception and re-raises a new one without from, discarding the original traceback and __cause__.

Sites:

Impact

Same as #2541: without from, Python shows "During handling of the above exception, another exception occurred" instead of "The above exception was the direct cause of the following exception." Callers cannot inspect __cause__ to determine the root cause programmatically.

The codebase already uses from correctly in server.py:451, server.py:459, server.py:1112, func_metadata.py:216,265, and tools/base.py:119. These 12 sites are the remaining inconsistencies.

まず、client/session.py、client/auth/utils.py、server/auth/middleware/client_auth.py、server/mcpserver/resources/types.py、resource_manager.py、templates.py、prompts/base.py にある、一覧に示された12か所を調査します。server.py、func_metadata.py、tools/base.py にある既存の使用例と比較します。各再送出例外が元の例外を直接の原因として保持し、関連するクライアントおよびサーバーの動作が引き続きパスすれば完了です。