Initial import of LogDarioSeq baseline

Establishes version control for the personal Logseq DB fork before
starting the server-client architecture migration and domain features
described in docs/agent-guide and the approved implementation plan.

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

deps/db-sync/src/logseq/db_sync/platform/node.cljs

@@ -0,0 +1,50 @@
+(ns logseq.db-sync.platform.node
+  (:require [clojure.string :as string]
+            [logseq.db-sync.platform.core :as core]
+            [promesa.core :as p]))
+
+(defn- headers->object [headers]
+  (let [out (js-obj)]
+    (.forEach headers (fn [value key] (aset out key value)))
+    out))
+
+(defn request-from-node
+  [^js req {:keys [scheme host]}]
+  (let [headers (js/Headers.)
+        node-headers (.-headers req)
+        header-keys (js/Object.keys node-headers)
+        _ (doseq [k header-keys]
+            (let [value (aget node-headers k)]
+              (when (some? value)
+                (.set headers (string/lower-case k) value))))
+        method (or (.-method req) "GET")
+        host (or host (aget node-headers "host") "localhost")
+        scheme (or scheme "http")
+        url (str scheme "://" host (.-url req))
+        init #js {:method method
+                  :headers headers}]
+    (when-not (or (= method "GET") (= method "HEAD"))
+      (aset init "body" req)
+      (aset init "duplex" "half"))
+    (core/request url init)))
+
+(defn send-response!
+  [^js res ^js response]
+  (let [headers (headers->object (.-headers response))
+        status (.-status response)]
+    (.writeHead res status headers)
+    (if-let [body (.-body response)]
+      (let [^js stream (try
+                         (let [Readable (.-Readable (js/require "stream"))]
+                           (when (and Readable (.-fromWeb Readable))
+                             (.fromWeb Readable body)))
+                         (catch :default _ nil))]
+        (if stream
+          (do
+            (.pipe stream res)
+            (js/Promise.resolve nil))
+          (p/let [buf (.arrayBuffer response)]
+            (.end res (js/Buffer.from buf)))))
+      (do
+        (.end res)
+        (js/Promise.resolve nil)))))