fix(ext-view): clear cross-engine error, propagate globals across JteExtension builder chain

- BaseViewExtension: wrap the ViewRuntimeBridge provider collision with a message
  naming the real constraint (one view engine per FlashApp) instead of the generic
  "duplicate provider" error.
- BaseViewExtension/JteExtension: carry registered globals across JteExtension's
  immutable settings builders (templateRoot/serveStatics/staticPrefix/withStaticCors/
  staticCors). addGlobal() called before any of those used to be silently dropped,
  since each builder method returned a fresh instance with an empty globals list.
- Correct flash-ext-view-jte docs (README, architecture.md, model-and-globals.md):
  globals merge flat with one typed @param per key, not under a global.* namespace
  like Thymeleaf — the docs previously claimed the same reserved namespace for both
  engines, which doesn't match JteRuntime's actual merge behavior.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

flash-extensions/flash-ext-view-jte/README.md

@@ -8,7 +8,7 @@ This module keeps jte semantics front and center:
 - `JteHandler`
 - `@Template`
 - `ViewModel` from `flash-ext-view-core`
-- `global.*` reserved namespace
+- globals merged flat into the model, one typed `@param` per global
 
 The extension mirrors `gg.jte.ContentType` into Flash HTTP content type:
 

flash-extensions/flash-ext-view-jte/docs/architecture.md

@@ -9,7 +9,7 @@
 
 2. **Request-time**
    - Handler builds local `ViewModel`.
-   - Runtime injects globals under reserved `global` namespace and merges local model.
+   - Runtime merges globals and local model into one flat parameter map (fails fast on key collision).
    - jte renders template into `StringOutput`.
 
 3. **Static assets (optional, enabled by default)**

flash-extensions/flash-ext-view-jte/docs/model-and-globals.md

@@ -28,6 +28,21 @@ Register globals in extension setup:
 new JteExtension().addGlobal("appName", req -> "Flash")
 ```
 
-Globals are available under `global` namespace in templates.
+Globals are merged **flat** into the model — same level as local `ViewModel` keys, not
+under a `global.*` namespace. jte templates are statically typed, so each template declares
+one `@param` per global it actually uses, named exactly like the global key:
 
-`global` is reserved and cannot be used as local model key.
+```jte
+@param String appName
+
+<span>${appName}</span>
+```
+
+A template that doesn't declare `appName` simply never sees it — no need to declare every
+global on every page, only the ones a given template actually uses.
+
+A local `ViewModel` key that collides with a registered global name fails fast with
+`IllegalStateException` at render time, so a typo can't silently shadow a global.
+
+Every registered global is still resolved on **every** render regardless of whether the
+target template declares it, so keep resolvers cheap (no blocking I/O, no heavy allocation).

flash-extensions/flash-ext-view-jte/src/main/java/dev/relism/flash/ext/view/jte/JteExtension.java

@@ -29,31 +29,32 @@ public final class JteExtension extends BaseViewExtension<JteTarget> {
         this.settings = builder.build();
     }
 
-    private JteExtension(JteSettings settings) {
+    private JteExtension(JteSettings settings, List<GlobalValue> seedGlobals) {
+        super(seedGlobals);
         this.settings = settings;
     }
 
     public JteExtension templateRoot(String templateRoot) {
-        return new JteExtension(settings.toBuilder().templateRoot(templateRoot).build());
+        return new JteExtension(settings.toBuilder().templateRoot(templateRoot).build(), globals());
     }
 
     public JteExtension serveStatics(boolean serveStatics) {
-        return new JteExtension(settings.toBuilder().serveStatics(serveStatics).build());
+        return new JteExtension(settings.toBuilder().serveStatics(serveStatics).build(), globals());
     }
 
     public JteExtension staticPrefix(String staticPrefix) {
-        return new JteExtension(settings.toBuilder().staticPrefix(staticPrefix).build());
+        return new JteExtension(settings.toBuilder().staticPrefix(staticPrefix).build(), globals());
     }
 
     public JteExtension withStaticCors() {
-        return new JteExtension(settings.toBuilder().enableStaticCors(true).build());
+        return new JteExtension(settings.toBuilder().enableStaticCors(true).build(), globals());
     }
 
     public JteExtension staticCors(Consumer<JteSettings.Builder> corsConfig) {
         JteSettings.Builder builder = settings.toBuilder();
         builder.enableStaticCors(true);
         corsConfig.accept(builder);
-        return new JteExtension(builder.build());
+        return new JteExtension(builder.build(), globals());
     }
 
     @Override

flash-extensions/flash-ext-view-jte/src/test/java/dev/relism/flash/ext/view/jte/JteExtensionTest.java

@@ -1,6 +1,11 @@
 package dev.relism.flash.ext.view.jte;
 
+import dev.relism.flash.ext.view.core.RenderedView;
 import dev.relism.flash.ext.view.core.ViewModel;
+import dev.relism.flash.ext.view.core.ViewRuntimeBridge;
+import dev.relism.flash.ext.view.jte.model.HomePage;
+import dev.relism.flash.extension.FlashContext;
+import dev.relism.flash.http.ContentType;
 import dev.relism.flash.models.Request;
 import dev.relism.flash.models.RequestHandler;
 import dev.relism.flash.models.Response;
@@ -89,6 +94,39 @@ class JteExtensionTest {
         assertEquals("https://cdn.example.com", settings.staticCorsAllowOrigin());
     }
 
+    @Test
+    void addGlobal_survives_subsequent_settings_builder_calls() throws Exception {
+        // addGlobal() before a chained settings method (templateRoot/serveStatics/...) used to
+        // be silently dropped: those methods return a *new* JteExtension instance, and the
+        // globals list lived on the instance, not the settings being carried forward.
+        JteExtension ext = new JteExtension(cfg -> cfg.developmentMode(true))
+                .addGlobal("appName", req -> "FlashLab")
+                .templateRoot("templates")
+                .serveStatics(false);
+
+        TestRegistrar app = new TestRegistrar();
+        FlashContext ctx = new FlashContext();
+        ext.configure(app, ctx);
+        ctx.complete();
+
+        @SuppressWarnings("unchecked")
+        ViewRuntimeBridge<JteTarget> runtime = (ViewRuntimeBridge<JteTarget>) ctx.require(ViewRuntimeBridge.class);
+
+        JteHandler handler = new JteHandler() {
+            @Override
+            public ViewModel render(Request req) {
+                return ViewModel.empty()
+                        .with("page", new HomePage("Flash + jte", "elorc"))
+                        .with("build", "dev");
+            }
+        };
+        JteTarget target = new JteTarget("pages/home.jte", ContentType.TEXT_HTML);
+        RenderedView out = runtime.render(handler, target, request("/", null, null, null),
+                new Response(200, ContentType.JSON));
+
+        assertTrue(out.body().contains("FlashLab"), "global registered before templateRoot() must survive");
+    }
+
     @Test
     void routes_register_static_wildcard_when_enabled() {
         JteExtension ext = new JteExtension(cfg -> cfg.staticPrefix("/assets"));