Add inject-transport-session pass to emit transport session IR

[mehrdad2m]

Context:
Backline places a QNode's controller and its coprocessors on separate executors that talk over a transport. The placement is serialized onto the module as the catalyst.backline attribute (controller + coprocessors + per-node backend/peer/triple/data-path info). This pass turns that declarative attribute into the concrete transport-dialect session lifecycle, wired into the setup/teardown functions the runtime already calls around every execution.

Description of the Change:
Reading catalyst.backline, the pass injects, per session:

bring-up into @setup: transport.create → connect → exchange_keys → establish_channel → commit_work_item (controller) / set_coprocessor_fn (coprocessor) → start
tear-down into @teardown: get_session → stop → destroy

Topologies handled:

• Controller-only: single controller session, straight-line bring-up/teardown.
• Local coprocessors: controller + coprocessor sessions created together in the host @setup; the coprocessor's connect/exchange_keys run async so the two ends handshake concurrently.
• Remote coprocessors: each coprocessor's ops go into a generated module_coproc tagged with its catalyst.target triple and catalyst.dispatch address; the host launches coproc_serve (nonblocking) / coproc_stop.
• Remote controller: the controller's ops go into its role-tagged target module as setup_transport/teardown_transport and the host @setup/@teardown become the single orchestration point that launches every dispatched role in dependency order (serve → controller setup; coproc stop → controller teardown), and @setup is marked catalyst.backline_bringup so the object-shipping pass knows where to ship from.

Benefits:

Possible Drawbacks:

Related GitHub Issues:

[rniczh]

Thanks @mehrdad2m

[multiphaseCFD]

Thanks @mehrdad2m ! Nice work!