feat(java): Separate the jdtls JDK and add Settings for New Projects (#21)

- Languages & Frameworks › Java › Language Server › JDK (languages.java.jdtlsJdk) runs jdtls on its own JDK, like IDEA's JDK for importer; the project keeps compiling and running with the Project JDK.
- Toolchain pages get the Global / This project switch (default This project); Global shows and edits the global layer.
- File › New Projects Setup › Settings for New Projects… edits only the global layer, which new projects inherit.
- Configuration errors (launch_error) show as "Not started" instead of "Crashed".

Fixes #18
Fixes #19

Claude-Session: https://claude.ai/code/session_01SaPPsVPuk6ZTNsoUCNCbMv

src/features/settings/window/SettingsWindow.tsx

@@ -4,7 +4,7 @@ import { OverlayHost } from "@/workbench/OverlayHost";
 import { usePlatform } from "@/platform/platformInfo";
 import { TitleBar } from "@/workbench/TitleBar";
 import { useApplyTheme } from "@/workbench/theme";
-import { SettingsFooter, SettingsLayout } from "../dialog/SettingsDialog";
+import { SettingsFooter, SettingsLayout, useSettingsTitle } from "../dialog/SettingsDialog";
 import { useSettingsDialog } from "../model/staging";
 import styles from "../dialog/SettingsDialog.module.css";
 
@@ -12,6 +12,7 @@ export function SettingsWindow() {
   useApplyTheme();
   const ownTitleBar = usePlatform((s) => s.overlayTitleBar || s.framelessTitleBar);
   const open = useSettingsDialog((s) => s.open);
+  const title = useSettingsTitle();
   const ref = useRef<HTMLDivElement>(null);
 
   useEffect(() => {
@@ -21,7 +22,7 @@ export function SettingsWindow() {
   return (
     <div ref={ref} className={styles.window}>
       {/* macOS overlays traffic lights on it; Windows is frameless. Linux keeps the OS title bar. */}
-      {ownTitleBar && <TitleBar minimal dialog title="Settings" />}
+      {ownTitleBar && <TitleBar minimal dialog title={title} />}
       {open && (
         <>
           <div className={styles.windowBody}>