Add the account area and account-synced Appearance preferences

Stage 1 PR 6 (ADR 0062). /account shows who is signed in; /account/appearance
chooses System, Light, or Dark and reduced motion (System, Reduce, Allow).

- Core: ekklesia_core_user_preference, one typed, CHECK-constrained,
  nullable column per preference (null = never chosen), migration
  0008_user_preferences (additive), @ekklesia/core/account store, and the
  authenticated-baseline permission core.account.self.manage.
- API: GET /api/v1/account (name, email, preferences) and partial
  PATCH /api/v1/account/preferences, self-only by construction: no user id
  is accepted anywhere; trusted Origin and body limit on the mutation.
- Shell: the account control shows name, email, and initials (never the
  unvetted image URL) and offers Account, Appearance, Sign out; native
  radio groups apply a choice at once through the ADR 0060 controller and
  save it; the server's answer wins and a failed save reverts.
- First paint: a classic, same-origin, render-blocking appearance.js in
  <head> applies a two-word localStorage cache before paint (no inline
  script, CSP unchanged). The account replaces the cache on every load,
  sign-out clears it, and other tabs follow via the storage event.
- Deploy smoke: real-Chromium checks for light/dark, OS emulation,
  overrides, reload persistence, pre-paint, Shadow DOM modules, reduced
  motion, the display staying light, and phone width; the browser
  container gets a 512 MiB /dev/shm so a long session no longer fails
  requests with ERR_INSUFFICIENT_RESOURCES.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

apps/api/src/dashboard-host-assets.ts

@@ -3,7 +3,9 @@ import { readFile } from "node:fs/promises";
 import { dashboardHostAssetUrls } from "@ekklesia/shell/dashboard-assets";
 
 /**
- * The two immutable, platform-owned files that make up the built Ekklesia Dashboard (ADR 0044).
+ * The three immutable, platform-owned files that make up the built Ekklesia Dashboard (ADR 0044):
+ * the page, its application script, and the small pre-paint appearance script the page loads in
+ * `<head>` (ADR 0062).
  *
  * Exactly the model `./display-host-assets.js` uses: read once, before the HTTP listener is bound,
  * from the exact URLs the surface package exports. Request input is never involved in this read, the
@@ -16,6 +18,8 @@ export interface DashboardHostAssets {
   readonly htmlEtag: string;
   readonly script: string;
   readonly scriptEtag: string;
+  readonly appearanceScript: string;
+  readonly appearanceScriptEtag: string;
 }
 
 /** A startup failure with a fixed, non-secret shape. The originating filesystem exception, package
@@ -42,11 +46,21 @@ function strongEtag(text: string): string {
  * can never be paired with an ETag from another. Empty output is a failed shell build rather than a
  * valid page that can never render anything.
  */
-export function createDashboardHostAssets(html: string, script: string): DashboardHostAssets {
-  if (html.trim().length === 0 || script.trim().length === 0) {
+export function createDashboardHostAssets(
+  html: string,
+  script: string,
+  appearanceScript: string,
+): DashboardHostAssets {
+  if (
+    html.trim().length === 0 ||
+    script.trim().length === 0 ||
+    appearanceScript.trim().length === 0
+  ) {
     throw new DashboardHostAssetError();
   }
   return Object.freeze({
+    appearanceScript,
+    appearanceScriptEtag: strongEtag(appearanceScript),
     html,
     htmlEtag: strongEtag(html),
     script,
@@ -92,7 +106,7 @@ export function renderDashboardPage(html: string, apiOrigin: string): string {
   return parts.join(`<meta content="${escaped}" name="ekklesia-api-origin" />`);
 }
 
-/** Loads only the two surface-declared files, and renders the API origin into the page. A missing,
+/** Loads only the three surface-declared files, and renders the API origin into the page. A missing,
  * unreadable, or incompatible build fails startup rather than leaving an API whose own origin answers
  * `/` with a 404 or a page that cannot find its API. */
 export async function loadDashboardHostAssets(apiOrigin: string): Promise<DashboardHostAssets> {
@@ -101,7 +115,12 @@ export async function loadDashboardHostAssets(apiOrigin: string): Promise<Dashbo
     // rejected sibling read is left running after this function has already failed.
     const html = await readFile(new URL(dashboardHostAssetUrls.html), "utf8");
     const script = await readFile(new URL(dashboardHostAssetUrls.script), "utf8");
-    return createDashboardHostAssets(renderDashboardPage(html, apiOrigin), script);
+    const appearanceScript = await readFile(new URL(dashboardHostAssetUrls.appearance), "utf8");
+    return createDashboardHostAssets(
+      renderDashboardPage(html, apiOrigin),
+      script,
+      appearanceScript,
+    );
   } catch {
     throw new DashboardHostAssetError();
   }