v2.3.0 — calls on one target run side by side over HTTPS

When vmware-log-insight mcp serves the network (--transport https or http), calls no longer queue behind each other.
Calls that name the same target, or name no target, now run side by side instead of one at a time (HLD §16
D-13(2), via vmware-policy 1.22.0):

• Each call gets its own session to the Log Insight for as long as it runs, so two calls never share a login.
• Each target keeps up to VMWARE_MCP_POOL_SIZE sessions (default 2). Each session is a login on the target, so
  raise it only as far as the account's session limit allows.
• A call that finds every session busy waits at most 300 s for one, then fails with a message saying so.
• A session that has expired or stopped answering is closed and replaced the next time a call needs it.

stdio and the CLI are unchanged: one session per target, reused.