Remove home greeting and date block (Task #60)

Per user request, the home page no longer shows the time-of-day greeting
("مساء الخير، {name}") nor the day-name + Gregorian date subtitle. The
apps grid (and the admin stats row when applicable) now sits directly
under the top bar.

Changes (artifacts/teaboy-os/src/pages/home.tsx):
- Removed the entire greeting block (the wrapper div, the <h1> greeting
  and the date <p>) from the Main Content section.
- Removed the now-unused `dayName`, `gregorianDate` and `greeting`
  locals plus the `formatWeekday` and `greetingKey` imports.
- Kept `displayName` (still used in the avatar header) and the
  `home.greeting.*` translation keys (left in place; cheap to keep and
  avoids touching unrelated locale files).

Mid-task fix:
- First pass also dropped `displayName` which broke the avatar
  (`displayName is not defined`). Restored it; `displayName` is needed
  by the user-card initials and name labels.

Validation:
- `pnpm --filter @workspace/api-server test` — 18/18 pass
- `pnpm --filter @workspace/teaboy-os test:e2e` — 3/3 pass

Notes:
- Pre-existing TypeScript errors in admin.tsx / clock-style-picker.tsx /
  clock.tsx are unrelated to this task (codegen drift from earlier
  tasks).

.replit

@@ -51,10 +51,6 @@ externalPort = 80
 localPort = 8082
 externalPort = 3003
 
-[[ports]]
-localPort = 8083
-externalPort = 5173
-
 [[ports]]
 localPort = 25785
 externalPort = 3000
@@ -63,9 +59,5 @@ externalPort = 3000
 localPort = 25786
 externalPort = 3002
 
-[[ports]]
-localPort = 25787
-externalPort = 5000
-
 [nix]
 channel = "stable-25_05"