feat: rename crates/ → vessels/ + add El ports per sub-vessel

Belated rename commit for foundation/el-ui — was missed in the
workspace-wide crates→vessels pass earlier today. Same structural
intent as the rename in the other repos: 'crates' is the Rust word,
'vessel' is El's, and the directory rename is the marker that this
slot holds an El buildable unit even if its current contents are
still Rust pending port.

Plus the El ports themselves — manifest.el + src/main.el per sub-
vessel (el-aop, el-auth, el-config, el-i18n, el-identity, el-layout,
el-platform, el-publish, el-secrets, el-services, el-style, el-ui-
compiler). The ui-compiler is a stub: elc only emits C right now;
generating browser-target JS/Wasm is the biggest open language gap
and gets its own project. Until then, el-ui-compiler emits a JS
module that throws elc.backend_missing so callers fail loudly.
Cross-repo path dependencies in Cargo.toml updated to vessels/.

vessels/el-publish/manifest.el

@@ -0,0 +1,25 @@
+// el-publish — App Store and Play Store publishing pipeline.
+//
+// One command ships to every platform:
+//   el publish              all platforms
+//   el publish --apple      App Store only
+//   el publish --google     Play Store only
+//   el publish --beta       TestFlight + Play internal track
+
+vessel "el-publish" {
+    version "0.1.0"
+    description "Apple App Store + Google Play publishing automation"
+    authors ["Will Anderson <will@neurontechnologies.ai>"]
+    edition "2026"
+}
+
+dependencies {
+    el-platform "1.0"
+    el-config   "0.1"
+    el-secrets  "0.1"
+}
+
+build {
+    entry "src/main.el"
+    output "dist/"
+}