CLAUDE: fix MCP dialog values silently discarded on submit

The registry entry is cleared by submitCurrent() (and again by
showDialog()) BEFORE applyCltDialog() runs the getNext*() reads, so
getValueOrDefault() - which looked the session up via the registry -
always saw null and fell back to every field's default: any value set
via POST /mcp/dialog/values was silently lost and OK re-applied the
loaded config. The dialog now keeps its OWN session reference for the
reads and the await; the registry cleanup clears only its own session
(covers the timeout path without clobbering a newer dialog).
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/main/java/com/elphel/imagej/common/GenericJTabbedDialogMcp.java

@@ -38,6 +38,7 @@ public class GenericJTabbedDialogMcp extends GenericJTabbedDialog{
 	private static long dialogTimeoutMs = 30000L;
 	public boolean mcp_mode = false;
 	private boolean mcpCanceled = false;
+	private McpDialogSession mcpSession = null; // this dialog's OWN session: the registry is cleared on submit BEFORE the getNext*() reads run, so reads must not go through it // By Claude on 07/07/2026
 	private final List<McpDialogField> mcpFields = new ArrayList<McpDialogField>();
 	private final String dialogTitle;
 	private String currentTab = "";
@@ -192,7 +193,8 @@ public class GenericJTabbedDialogMcp extends GenericJTabbedDialog{
 		if (mcp_mode) {
 			// codex 2026-01-25: publish dialog schema to MCP registry
 			readIndex = 0;
-			boolean applied = McpDialogRegistry.setCurrent(new McpDialogSession(dialogTitle, mcpFields));
+			mcpSession = new McpDialogSession(dialogTitle, mcpFields); // By Claude on 07/07/2026: keep own reference (see field comment)
+			boolean applied = McpDialogRegistry.setCurrent(mcpSession);
 			if (!applied) {
 				System.out.println("MCP: dialog already active, ignoring \"" + dialogTitle + "\"");
 			}
@@ -218,7 +220,7 @@ public class GenericJTabbedDialogMcp extends GenericJTabbedDialog{
 	}
 
 	private String getValueOrDefault(McpDialogField field) {
-		McpDialogSession session = McpDialogRegistry.getCurrent();
+		McpDialogSession session = mcpSession; // By Claude on 07/07/2026: was McpDialogRegistry.getCurrent() - always null here (registry cleared on submit before the reads), so /mcp/dialog/values was silently discarded
 		if (session != null && field != null) {
 			String value = session.getValue(field.label);
 			if (value != null) {
@@ -299,7 +301,7 @@ public class GenericJTabbedDialogMcp extends GenericJTabbedDialog{
 	public boolean showDialog() {
 		if (mcp_mode) {
 			buildDialog();
-			McpDialogSession session = McpDialogRegistry.getCurrent();
+			McpDialogSession session = mcpSession; // By Claude on 07/07/2026: own session (registry may hold another dialog / be cleared by submit)
 			if (session != null) {
 				long timeout = dialogTimeoutMs;
 				Boolean ok = (timeout <= 0) ? session.awaitSubmit(Long.MAX_VALUE) : session.awaitSubmit(timeout);
@@ -309,7 +311,9 @@ public class GenericJTabbedDialogMcp extends GenericJTabbedDialog{
 					mcpCanceled = false;
 				}
 			}
-			McpDialogRegistry.setCurrent(null);
+			if (McpDialogRegistry.getCurrent() == mcpSession) { // By Claude on 07/07/2026: clear only OUR session (submit normally cleared it; this covers the timeout path without clobbering a newer dialog)
+				McpDialogRegistry.setCurrent(null);
+			}
 			return true;
 		}
 		else return super.showDialog();