fix: set EventBridge schedule to 5 minutes to match Lambda timeout

Lambda timeout is 300s (5 min). Running at 1 min intervals would cause
concurrent executions overlapping — set schedule to rate(5 minutes) to
ensure each invocation completes before the next one starts.

bootstrap-dynamodb.sh now also configures:
- EventBridge rule (rate(5 minutes))
- Lambda permission for EventBridge invocation
- Lambda timeout enforcement (300s)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: jckdotim

infra/bootstrap-dynamodb.sh

@@ -1,10 +1,18 @@
 #!/bin/bash
-# Creates bridge-monitor-state and bridge-exchange-histories DynamoDB tables
-# Usage: AWS_REGION=us-east-1 bash bootstrap-dynamodb.sh
+# Creates bridge-monitor-state and bridge-exchange-histories DynamoDB tables,
+# and sets up the EventBridge rule to trigger the Lambda every 5 minutes.
+#
+# Lambda timeout must be set to 5 minutes (300s) to match the schedule interval.
+# EventBridge fires every 5 minutes — Lambda must finish before the next invocation.
+#
+# Usage:
+#   AWS_REGION=us-east-1 LAMBDA_FUNCTION_NAME=bridge-relayer bash bootstrap-dynamodb.sh
 
 set -e
 
 REGION="${AWS_REGION:-us-east-1}"
+LAMBDA_FUNCTION_NAME="${LAMBDA_FUNCTION_NAME:-bridge-relayer}"
+SCHEDULE_EXPRESSION="rate(5 minutes)"  # Must match Lambda timeout (300s)
 
 echo "Creating DynamoDB tables in region: ${REGION}"
 
@@ -55,3 +63,57 @@ echo "bridge-exchange-histories created."
 
 echo ""
 echo "All DynamoDB tables created successfully."
+
+# --- EventBridge rule: invoke Lambda every 5 minutes ---
+echo ""
+echo "Setting up EventBridge schedule (${SCHEDULE_EXPRESSION})..."
+
+RULE_NAME="bridge-relayer-schedule"
+
+RULE_ARN=$(aws events put-rule \
+  --region "$REGION" \
+  --name "$RULE_NAME" \
+  --schedule-expression "$SCHEDULE_EXPRESSION" \
+  --state ENABLED \
+  --description "Triggers bridge-relayer Lambda every 5 minutes" \
+  --query 'RuleArn' \
+  --output text)
+
+echo "EventBridge rule created: ${RULE_ARN}"
+
+LAMBDA_ARN=$(aws lambda get-function \
+  --region "$REGION" \
+  --function-name "$LAMBDA_FUNCTION_NAME" \
+  --query 'Configuration.FunctionArn' \
+  --output text)
+
+# Allow EventBridge to invoke the Lambda
+aws lambda add-permission \
+  --region "$REGION" \
+  --function-name "$LAMBDA_FUNCTION_NAME" \
+  --statement-id "AllowEventBridgeInvoke" \
+  --action "lambda:InvokeFunction" \
+  --principal "events.amazonaws.com" \
+  --source-arn "$RULE_ARN" \
+  2>/dev/null || echo "  (permission already exists, skipping)"
+
+aws events put-targets \
+  --region "$REGION" \
+  --rule "$RULE_NAME" \
+  --targets "Id=bridge-relayer-target,Arn=${LAMBDA_ARN}"
+
+echo "EventBridge rule wired to Lambda: ${LAMBDA_FUNCTION_NAME}"
+
+# --- Lambda timeout: enforce 300s (5 minutes) ---
+echo ""
+echo "Setting Lambda timeout to 300s..."
+aws lambda update-function-configuration \
+  --region "$REGION" \
+  --function-name "$LAMBDA_FUNCTION_NAME" \
+  --timeout 300
+
+echo ""
+echo "Bootstrap complete."
+echo "  Schedule : ${SCHEDULE_EXPRESSION}"
+echo "  Lambda   : ${LAMBDA_FUNCTION_NAME} (timeout: 300s)"
+echo "  Tables   : bridge-monitor-state, bridge-exchange-histories"