fix(async): convert PoA proposer methods to async and update coordinator dependencies

- Convert _propose_block, _ensure_genesis_block to async methods in PoAProposer
- Add await to gossip_broker.publish calls in block broadcasting
- Add await to _ensure_genesis_block and _propose_block method calls
- Update coordinator-api Python version constraint to >=3.13,<3.15
- Add torch ^2.10.0 dependency to coordinator-api
- Add make_asgi_app import to prometheus_client in main.py
- Export new routers: global

fix_gossip.patch

@@ -0,0 +1,20 @@
+--- a/apps/blockchain-node/src/aitbc_chain/consensus/poa.py
++++ b/apps/blockchain-node/src/aitbc_chain/consensus/poa.py
+@@ -171,7 +171,7 @@
+             )
+             
+             # Broadcast the new block
+-            gossip_broker.publish(
++            await gossip_broker.publish(
+                 "blocks",
+                 {
+                     "height": block.height,
+@@ -207,7 +207,7 @@
+             session.commit()
+             
+             # Broadcast genesis block for initial sync
+-            gossip_broker.publish(
++            await gossip_broker.publish(
+                 "blocks",
+                 {
+                     "height": genesis.height,