PMCP pilot rehearsal: configurable Qdrant ports (host-mode clash with dev0 :6334) #138

During delivered acceptance of 1.5.0, 1.5.1 and 1.6.0, the PMCP pilot's rehearsal mode couldn't run on the shared dev0 host.

• Bridge publishing broken: dev0's Docker can't reach ports published from the default bridge network. A plain web server in the same image shows the same connection reset.
• Host-mode port clash: with --docker-network host, the pilot doesn't set Qdrant's gRPC port, so its Qdrant would bind 127.0.0.1:6334. On dev0 that's the port of the live mcp_qdrant, which is currently stopped by owner decision. Holding it could stop that container from restarting.

Fix

• Give scripts/v13_pmcp_pilot.py rehearsal configurable Qdrant HTTP and gRPC ports, defaulting to free ephemeral ones in host mode. Fail fast if a port is taken instead of colliding.
• Optionally document or diagnose dev0's bridge-publishing problem separately; it's host networking, not Code-Index-MCP.
• Then re-run rehearsal against the published 1.6.0 to complete its delivered acceptance. This goes with PMCP pilot: move from pmcp 2.7.3 to 3.x and re-run offline/rehearsal acceptance #133, the move to pmcp 3.x.