feat: port el-ui vessels — rename crates→vessels, add El source + manifests

ui/vessels/el-platform/manifest.el

@@ -0,0 +1,23 @@
+// el-platform — Platform abstraction surface for el-ui.
+//
+// Wraps the El runtime's filesystem, network, environment, and clock
+// primitives behind a stable API so application vessels depend on this
+// vessel rather than runtime builtin names directly.
+//
+// The Rust crate also implements per-target render backends
+// (web/server/ios/android/macos/linux/windows). At the El layer the
+// target is fixed at compile time — the runtime IS the backend — so no
+// `PlatformBackend` polymorphism is exposed here. DOM patching and native
+// widget mounting will arrive once el-ui-compiler emits browser/native code.
+
+vessel "el-platform" {
+    version "1.0.0"
+    description "Platform abstraction: env, filesystem, network, clock, UUID"
+    authors ["Will Anderson <will@neurontechnologies.ai>"]
+    edition "2026"
+}
+
+build {
+    entry "src/main.el"
+    output "dist/"
+}