fix(driver): avoid false agent update prompt

Fixes #638

crates/dbx-core/src/agent_service.rs

@@ -46,6 +46,7 @@ impl AgentProgressEvent {
 
 pub fn build_agent_list(am: &AgentManager, registry: Option<&AgentRegistry>) -> Vec<AgentDriverInfo> {
     let local_state = am.load_state();
+    let use_managed_jre = local_state.java_runtime.mode == JavaRuntimeMode::Managed;
     agent_catalog::driver_store_entries()
         .map(|(key, label)| {
             let installed = am.is_driver_installed(key);
@@ -56,8 +57,9 @@ pub fn build_agent_list(am: &AgentManager, registry: Option<&AgentRegistry>) ->
                 .or_else(|| local.map(|l| l.jre.clone()))
                 .unwrap_or_else(|| DEFAULT_JRE_KEY.to_string());
             let remote_jre_version = registry.and_then(|r| r.resolve_jre(&jre_key)).map(|j| &j.version);
-            let local_jre_version = local_state.jre_versions.get(&jre_key);
+            let local_jre_version = installed_jre_version(&local_state, &jre_key);
             let jre_update_available = installed
+                && use_managed_jre
                 && (!am.is_jre_installed(&jre_key)
                     || remote_jre_version.is_some_and(|version| local_jre_version != Some(version)));
             AgentDriverInfo {
@@ -78,6 +80,13 @@ pub fn build_agent_list(am: &AgentManager, registry: Option<&AgentRegistry>) ->
         .collect()
 }
 
+fn installed_jre_version<'a>(state: &'a crate::agent_manager::AgentState, jre_key: &str) -> Option<&'a String> {
+    state
+        .jre_versions
+        .get(jre_key)
+        .or_else(|| (jre_key == DEFAULT_JRE_KEY).then_some(state.jre_version.as_ref()).flatten())
+}
+
 pub fn jre_needs_install(am: &AgentManager, registry: &AgentRegistry, jre_key: &str) -> bool {
     let state = am.load_state();
     if state.java_runtime.mode != JavaRuntimeMode::Managed {

crates/dbx-core/tests/agent_service.rs

@@ -1,5 +1,6 @@
 use dbx_core::agent_manager::{
-    AgentManager, AgentRegistry, ArtifactInfo, DriverInfo, InstalledDriver, JreInfo, DEFAULT_JRE_KEY,
+    AgentManager, AgentRegistry, ArtifactInfo, DriverInfo, InstalledDriver, JavaRuntimeConfig, JavaRuntimeMode,
+    JreInfo, DEFAULT_JRE_KEY,
 };
 use dbx_core::agent_service::{
     build_agent_list, github_url_to_r2_path, import_agent_jar, import_agents_from_zip, is_app_version_compatible,
@@ -113,6 +114,71 @@ fn agent_list_marks_update_when_installed_managed_jre_version_differs() {
     assert!(h2.update_available);
 }
 
+#[test]
+fn agent_list_does_not_mark_jre_update_for_system_java_runtime() {
+    let manager = test_manager("system-java-no-jre-update");
+    let jar_path = manager.driver_jar_path("dameng");
+    std::fs::create_dir_all(jar_path.parent().unwrap()).unwrap();
+    std::fs::write(&jar_path, b"jar").unwrap();
+    manager
+        .save_state(&dbx_core::agent_manager::AgentState {
+            java_runtime: JavaRuntimeConfig { mode: JavaRuntimeMode::System, custom_java_path: None },
+            installed_drivers: [(
+                "dameng".to_string(),
+                InstalledDriver {
+                    version: "0.2.0".to_string(),
+                    installed_at: "2026-05-18T00:00:00Z".to_string(),
+                    jre: DEFAULT_JRE_KEY.to_string(),
+                },
+            )]
+            .into_iter()
+            .collect(),
+            ..Default::default()
+        })
+        .unwrap();
+    let registry = registry_with_jre_driver("dameng", "0.2.0", DEFAULT_JRE_KEY, "21.0.11");
+
+    let agents = build_agent_list(&manager, Some(&registry));
+    let dameng = agents.iter().find(|agent| agent.db_type == "dameng").unwrap();
+
+    assert!(dameng.installed);
+    assert!(!dameng.jre_installed);
+    assert!(!dameng.update_available);
+}
+
+#[test]
+fn agent_list_uses_legacy_default_jre_version_when_checking_updates() {
+    let manager = test_manager("legacy-jre-version");
+    let jar_path = manager.driver_jar_path("dameng");
+    let java_path = manager.jre_java_path(DEFAULT_JRE_KEY);
+    std::fs::create_dir_all(jar_path.parent().unwrap()).unwrap();
+    std::fs::create_dir_all(java_path.parent().unwrap()).unwrap();
+    std::fs::write(&jar_path, b"jar").unwrap();
+    std::fs::write(&java_path, b"java").unwrap();
+    manager
+        .save_state(&dbx_core::agent_manager::AgentState {
+            jre_version: Some("21.0.11".to_string()),
+            installed_drivers: [(
+                "dameng".to_string(),
+                InstalledDriver {
+                    version: "0.2.0".to_string(),
+                    installed_at: "2026-05-18T00:00:00Z".to_string(),
+                    jre: DEFAULT_JRE_KEY.to_string(),
+                },
+            )]
+            .into_iter()
+            .collect(),
+            ..Default::default()
+        })
+        .unwrap();
+    let registry = registry_with_jre_driver("dameng", "0.2.0", DEFAULT_JRE_KEY, "21.0.11");
+
+    let agents = build_agent_list(&manager, Some(&registry));
+    let dameng = agents.iter().find(|agent| agent.db_type == "dameng").unwrap();
+
+    assert!(!dameng.update_available);
+}
+
 #[test]
 fn jre_needs_install_when_managed_runtime_version_differs() {
     let manager = test_manager("jre-needs-install");