feat: use UDP rendezvous for git pre-push hook

Replaces the Python-based pre-push hook and long-polling HTTP logic with a native shell script using udp-send --wait to block on an ephemeral UDP port in the kernel. mcp-memory-server acts as the broker and replies to subscribers.

scripts/git-pre-push.sh

@@ -0,0 +1,45 @@
+#!/bin/bash
+# Native shell pre-push hook using UDP Rendezvous
+
+PORT=${MCP_UDP_PORT1:-3001}
+
+while read local_ref local_sha remote_ref remote_sha; do
+    if [ "$local_sha" = "0000000000000000000000000000000000000000" ] || [ "$local_ref" = "(delete)" ]; then
+        continue
+    fi
+    if [[ "$local_ref" == refs/tags/* ]]; then
+        continue
+    fi
+    
+    BRANCH=${local_ref#refs/heads/}
+    
+    echo -e "\033[36m[Pre-Push Gatekeeper]\033[0m Checking gate for branch '$BRANCH'..."
+    
+    # Check if gate is already authorized or blocked
+    if mcp-memory-server gate verify --action push --target "$BRANCH" --consume 2>/dev/null; then
+        echo -e "\033[32m[Pre-Push Gatekeeper]\033[0m Push AUTHORIZED by MCP Memory gate for branch '$BRANCH'."
+        continue
+    else
+        EXIT_CODE=$?
+        if [ $EXIT_CODE -eq 1 ]; then
+            echo -e "\033[31m[Pre-Push Gatekeeper]\033[0m Push BLOCKED by MCP Memory gate for branch '$BRANCH'."
+            exit 1
+        fi
+        
+        # If exit code is 2 (Not Found), we wait via UDP Rendezvous
+        echo -e "\033[33m[Pre-Push Gatekeeper]\033[0m No pre-authorized gate for '$BRANCH'. Waiting for approval via UDP rendezvous..."
+        
+        # Payload for UDP
+        PAYLOAD="{\"type\":\"gate_wait\",\"action\":\"push\",\"target\":\"$BRANCH\"}"
+        
+        if udp-send --wait "$PORT" "$PAYLOAD"; then
+            echo -e "\033[32m[Pre-Push Gatekeeper]\033[0m Push AUTHORIZED via UDP rendezvous for branch '$BRANCH'."
+            continue
+        else
+            echo -e "\033[31m[Pre-Push Gatekeeper]\033[0m Push DENIED or timed out via UDP rendezvous for branch '$BRANCH'."
+            exit 1
+        fi
+    fi
+done
+
+exit 0