Release DFTE v1.2.0

docs/ASYNC_WEB.md

@@ -24,6 +24,54 @@ void sendTemplate(AsyncWebServerRequest* request, const char* root) {
 
 The response retains the context while it streams. Releasing the request-owned `shared_ptr` on disconnect prevents state from leaking into later requests.
 
+## Bounded fixed slots
+
+Use `beginBorrowedChunkedResponse()` when the application already owns a small, fixed response pool. It does not allocate a `shared_ptr` control block for the request. The release callback must be idempotent because it can run once when rendering finishes and again if the connection later disconnects.
+
+```cpp
+struct ResponseSlot {
+    bool busy = false;
+    TemplateContext context;
+};
+
+ResponseSlot slots[2];
+
+void releaseSlot(ResponseSlot& slot) {
+    slot.context.reset();
+    slot.busy = false;
+}
+
+void sendBoundedTemplate(AsyncWebServerRequest* request, const char* root) {
+    ResponseSlot* slot = nullptr;
+    for (auto& candidate : slots) {
+        if (!candidate.busy) {
+            slot = &candidate;
+            break;
+        }
+    }
+    if (slot == nullptr) {
+        request->send(503, "text/plain", "Busy");
+        return;
+    }
+
+    slot->busy = true;
+    slot->context.setRegistry(registry.get());
+    TemplateRenderer::initializeContext(slot->context, root);
+    request->send(TemplateEngineAsyncWeb::beginBorrowedChunkedResponse(
+        request, "text/html; charset=utf-8", slot,
+        [](ResponseSlot& state, uint8_t* out, size_t size, size_t) {
+            return TemplateEngineAsyncWeb::renderTemplateChunkWithRetries(
+                state.context, out, size, 128);
+        },
+        [](const ResponseSlot& state) {
+            return TemplateEngineAsyncWeb::isTemplateTerminal(state.context);
+        },
+        releaseSlot));
+}
+```
+
+Use this form only while the slot itself has static or otherwise guaranteed lifetime. Use the `shared_ptr` form above for a request-owned dynamic context.
+
 Use [StreamingAsync](../examples/StreamingAsync/) for a complete SoftAP/captive-portal project.
 
 Back to [documentation](README.md) · [project overview](../README.md).