fix(mcp): align SDK and wire streamable server manually

- align all io.modelcontextprotocol.sdk artifacts to 0.18.1 via
  dependencyManagement so Spring AI transitives no longer pull mcp 0.10.0
- exclude Spring AI's legacy MCP server/webmvc auto-config, which is binary-
  incompatible with the 0.18.1 streamable transport APIs
- build McpSyncServer directly against WebMvcStreamableServerTransportProvider
  and adapt Spring AI ToolCallbacks to MCP SyncToolSpecifications manually
- keep /mcp as the sole Streamable HTTP endpoint for both initialize/tool calls
  and optional SSE event streams
- update MCP transport documentation to match the new runtime

Validated locally with:
- POST /mcp initialize -> HTTP 200 + Mcp-Session-Id
- POST /mcp tools/list -> returns resolve-library-id + get-library-docs

trueref-adapters/pom.xml

@@ -57,12 +57,10 @@
         <dependency>
             <groupId>io.modelcontextprotocol.sdk</groupId>
             <artifactId>mcp-spring-webmvc</artifactId>
-            <version>0.18.1</version>
         </dependency>
         <dependency>
             <groupId>io.modelcontextprotocol.sdk</groupId>
             <artifactId>mcp-json-jackson2</artifactId>
-            <version>0.18.1</version>
         </dependency>
 
         <!-- H2 + Flyway -->