Implemented the approved compatibility-first reliability improvements. - #3

Key changes:

• Prevented truncated/EOF responses from looping indefinitely; exact reads now fail with IOException and flow through existing client error handling.
• Preserved ROMA wire framing; added regression tests for exact get and set ESC/CRLF request bytes.
• Fixed optimized multi-get connection leaks: healthy connections return to the pool; failed ones are invalidated; socket timeouts are applied.
• Made optimized executor lifecycle safer and preserved interruption.
• Improved socket-pool validation and close behavior.
• Repaired HashMapConnectionPoolImpl cleanup, invalidation, idle-size enforcement, and socket closure.
• Made retry/settings visibility safer and preserved thread interrupts.
• Improved routing updater shutdown and protected routing-node list exposure.
• Allowed a closed RomaClientImpl to be opened again without nulling its routing table.