feat: synchronous replay endpoint with agent response status

Add dedicated POST /agents/{id}/replay endpoint that uses
addCommandWithReply to wait for the agent ACK (30s timeout).
Returns the actual replay result (status, message, data) instead
of just a delivery confirmation.

Frontend toast now reflects the agent's response: "Replay completed"
on success, agent error message on failure, timeout message if the
agent doesn't respond.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

cameleer3-server-app/src/main/java/com/cameleer3/server/app/dto/ReplayRequest.java

@@ -0,0 +1,18 @@
+package com.cameleer3.server.app.dto;
+
+import io.swagger.v3.oas.annotations.media.Schema;
+import jakarta.validation.constraints.NotNull;
+
+import java.util.Map;
+
+@Schema(description = "Request to replay an exchange on an agent")
+public record ReplayRequest(
+        @NotNull @Schema(description = "Camel route ID to replay on")
+        String routeId,
+        @Schema(description = "Message body for the replayed exchange")
+        String body,
+        @Schema(description = "Message headers for the replayed exchange")
+        Map<String, String> headers,
+        @Schema(description = "Exchange ID of the original execution being replayed (for audit trail)")
+        String originalExchangeId
+) {}

cameleer3-server-app/src/main/java/com/cameleer3/server/app/dto/ReplayResponse.java

@@ -0,0 +1,13 @@
+package com.cameleer3.server.app.dto;
+
+import io.swagger.v3.oas.annotations.media.Schema;
+
+@Schema(description = "Result of a replay command")
+public record ReplayResponse(
+        @Schema(description = "Replay outcome: SUCCESS or FAILURE")
+        String status,
+        @Schema(description = "Human-readable result message")
+        String message,
+        @Schema(description = "Structured result data from the agent (JSON)")
+        String data
+) {}