Add full shell, replaceable Omics adapter and bilingual interaction

Implement approved specification #32 and tickets #33-#37. Keep host authentication server-verified and pin session interaction language. Compile scoped base selectors for browser compatibility and retain full gutters during CSS pruning.

frontend/src/api/sessions.ts

@@ -1,4 +1,5 @@
 import { apiFetch } from "./client";
+import { getLocale } from "../i18n";
 import {
   captureAuthOperation,
   isAuthOperationCurrent,
@@ -93,6 +94,7 @@ async function ensureWorkspaceSelectionPolicy(precondition?: AuthOperationPrecon
 }
 
 export async function createSession(i: NewSessionInput, precondition?: AuthOperationPrecondition) {
+  const interactionLanguage = getLocale();
   const initiatingOperation = captureAuthOperation();
   const effectivePrecondition = precondition ?? (initiatingOperation ? {
     operation: initiatingOperation,
@@ -108,7 +110,7 @@ export async function createSession(i: NewSessionInput, precondition?: AuthOpera
   requireAuthOperationPrecondition(effectivePrecondition);
   return apiFetch<{ id: string }>("/sessions", {
     method: "POST",
-    body: JSON.stringify({ ...i, ...selection }),
+    body: JSON.stringify({ ...i, ...selection, interactionLanguage }),
   });
 }