fix: commands respect selected environment

Backend: AgentRegistryService gains findByApplicationAndEnvironment()
and environment-aware addGroupCommandWithReplies() overload.
AgentCommandController and ApplicationConfigController accept optional
environment query parameter. When set, commands only target agents in
that environment. Backward compatible — null means all environments.

Frontend: All command mutations (config update, route control, traced
processors, tap config, route recording) now pass selectedEnv to the
backend via query parameter.

Prevents cross-environment command leakage — e.g., updating config for
prod no longer pushes to dev agents.

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

cameleer3-server-core/src/main/java/com/cameleer3/server/core/agent/AgentRegistryService.java

@@ -214,6 +214,16 @@ public class AgentRegistryService {
                 .toList();
     }
 
+    /**
+     * Return all agents belonging to the given application and environment.
+     */
+    public List<AgentInfo> findByApplicationAndEnvironment(String application, String environment) {
+        return agents.values().stream()
+                .filter(a -> application.equals(a.applicationId()))
+                .filter(a -> environment.equals(a.environmentId()))
+                .toList();
+    }
+
     /**
      * Add a command to an agent's pending queue.
      * Notifies the event listener if one is set.
@@ -336,8 +346,21 @@ public class AgentRegistryService {
      */
     public Map<String, CompletableFuture<CommandReply>> addGroupCommandWithReplies(
             String group, CommandType type, String payload) {
+        return addGroupCommandWithReplies(group, null, type, payload);
+    }
+
+    /**
+     * Send a command to all LIVE agents in a group, optionally filtered by environment.
+     * When environment is null, targets all agents for the application.
+     * Returns a map of agentId -> CompletableFuture&lt;CommandReply&gt;.
+     */
+    public Map<String, CompletableFuture<CommandReply>> addGroupCommandWithReplies(
+            String group, String environment, CommandType type, String payload) {
         Map<String, CompletableFuture<CommandReply>> results = new LinkedHashMap<>();
-        List<AgentInfo> liveAgents = findByApplication(group).stream()
+        List<AgentInfo> candidates = environment != null
+                ? findByApplicationAndEnvironment(group, environment)
+                : findByApplication(group);
+        List<AgentInfo> liveAgents = candidates.stream()
                 .filter(a -> a.state() == AgentState.LIVE)
                 .toList();