feat: rename agent identity fields for protocol v2 + add SHUTDOWN lifecycle state

Align all internal naming with the agent team's protocol v2 identity rename:
- agentId → instanceId (unique per-JVM identifier)
- applicationName → applicationId (shared app identifier)
- AgentInfo: id → instanceId, name → displayName, application → applicationId

Add SHUTDOWN lifecycle state for graceful agent shutdowns:
- New POST /data/events endpoint receives agent lifecycle events
- AGENT_STOPPED event transitions agent to SHUTDOWN (skips STALE/DEAD)
- New POST /{id}/deregister endpoint removes agent from registry
- Server now distinguishes graceful shutdown from crash (heartbeat timeout)

Includes ClickHouse V9 and PostgreSQL V14 migrations for column renames.

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

cameleer3-server-app/src/main/java/com/cameleer3/server/app/agent/AgentLifecycleMonitor.java

@@ -39,7 +39,7 @@ public class AgentLifecycleMonitor {
             // Snapshot states before lifecycle check
             Map<String, AgentState> statesBefore = new HashMap<>();
             for (AgentInfo agent : registryService.findAll()) {
-                statesBefore.put(agent.id(), agent.state());
+                statesBefore.put(agent.instanceId(), agent.state());
             }
 
             registryService.checkLifecycle();
@@ -47,12 +47,12 @@ public class AgentLifecycleMonitor {
 
             // Detect transitions and record events
             for (AgentInfo agent : registryService.findAll()) {
-                AgentState before = statesBefore.get(agent.id());
+                AgentState before = statesBefore.get(agent.instanceId());
                 if (before != null && before != agent.state()) {
                     String eventType = mapTransitionEvent(before, agent.state());
                     if (eventType != null) {
-                        agentEventService.recordEvent(agent.id(), agent.application(), eventType,
-                                agent.name() + " " + before + " -> " + agent.state());
+                        agentEventService.recordEvent(agent.instanceId(), agent.applicationId(), eventType,
+                                agent.displayName() + " " + before + " -> " + agent.state());
                     }
                 }
             }