feat(activities): brand-kit logo + app name in the events page header

Replace the bare "Events" h1 with the brand-kit logo paired with the
standalone's localized name. Deployers get per-standalone logo
control via branding/<dep>/icons/events/logo.{svg,png}; the
component itself stays brand-agnostic.

Brand-kit plumbing:

- `resolveAppLogo(app?)` in vite-branding.ts mirrors the resolution
  chain pwa-assets.config.ts already uses for PWA icons
  (per-standalone svg → png → global svg → png).
- `brandAppLogoAliasEntry(app)` returns a vite alias array entry. A
  regex matches `@brand-app-logo` with or without a `?url` query so
  the file resolves cleanly under either form.
- vite.events.config.ts switches its resolve.alias to the array form
  so the per-standalone regex doesn't clash with the bare `@brand`
  string alias.

Component side: a single `import brandAppLogoUrl from '@brand-app-logo?url'`
gives EventsPage the best-resolved logo without any fallback chain
in the component.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

vite-branding.ts

@@ -1,6 +1,6 @@
 import { spawnSync } from 'node:child_process'
-import { readFileSync } from 'node:fs'
-import { resolve } from 'node:path'
+import { existsSync, readFileSync } from 'node:fs'
+import { join, resolve } from 'node:path'
 import type { Plugin } from 'vite'
 
 /**
@@ -43,6 +43,55 @@ export const brandAlias = {
   '@brand': BRAND_DIR,
 } as const
 
+/**
+ * Resolution order for the in-app logo of a given standalone. Mirrors
+ * what pwa-assets.config.ts does for PWA icons: per-standalone override
+ * first (SVG then PNG), then the brand's primary logo (SVG then PNG).
+ *
+ * Returned path is absolute so vite alias can map directly to it.
+ */
+export function resolveAppLogo(app?: string): string {
+  const candidates: string[] = []
+  if (app) {
+    candidates.push(
+      join(BRAND_DIR, 'icons', app, 'logo.svg'),
+      join(BRAND_DIR, 'icons', app, 'logo.png'),
+    )
+  }
+  candidates.push(
+    join(BRAND_DIR, 'logo.svg'),
+    join(BRAND_DIR, 'logo.png'),
+  )
+  const found = candidates.find((p) => existsSync(p))
+  if (!found) {
+    throw new Error(
+      `No brand logo found for app="${app ?? ''}". Tried:\n  ${candidates.join('\n  ')}\n` +
+        `See branding/README.md for the brand kit contract.`,
+    )
+  }
+  return found
+}
+
+/**
+ * Standalone-aware brand-logo alias entry. Append to a vite config's
+ * `resolve.alias` array alongside the rest of the alias map. The
+ * regex matches `@brand-app-logo` with or without a `?url` query so
+ * `import logoUrl from '@brand-app-logo?url'` resolves to the active
+ * standalone's logo file (per-app override or global), with no
+ * fallback chain in the component itself.
+ *
+ * Note: when used with the object form of resolve.alias, a bare
+ * `@brand` entry would shadow this — combine the two as an array
+ * (see vite.events.config.ts).
+ */
+export function brandAppLogoAliasEntry(app?: string) {
+  const resolved = resolveAppLogo(app)
+  return {
+    find: /^@brand-app-logo(\?.*)?$/,
+    replacement: `${resolved}$1`,
+  } as const
+}
+
 /**
  * PWA manifest name for a standalone. Combines the brand name with the
  * app's own label, or returns the bare brand when no label is given.