Let admins pick the time range for dashboard trends

Original task: Add a 7d/30d/90d range selector to the admin dashboard
trend cards/chart and have /stats/admin accept a matching range parameter.

Changes:
- OpenAPI (lib/api-spec/openapi.yaml): added optional `range` query
  parameter (enum 7d|30d|90d, default 7d) to GET /stats/admin and
  refactored AdminStats fields to be range-agnostic — added `range`
  and `rangeDays`, renamed `*Last7Days`/`*Prev7Days` to `*InRange`/
  `*PrevRange`. Regenerated api-client-react and api-zod.
- API server (artifacts/api-server/src/routes/stats.ts): parses and
  validates the `range` param, computes range/prev-range windows
  generically, and returns daily series sized to rangeDays.
- Admin UI (artifacts/teaboy-os/src/pages/admin.tsx): adds a segmented
  range selector at the top of the dashboard, passes the selected
  range into the stats query (with proper queryKey), and adapts the
  trend chart for denser ranges (skipped per-bar count text >14 days,
  every-Nth date label, month/day formatting for 30d/90d).
- Locale files (en.json/ar.json): added range/prevRange labels,
  trends/rangeSelector strings, and *Ranged variants of summary keys.
  Old keys kept to avoid stale references.

Verification:
- pnpm typecheck passes across libs and artifacts.
- e2e test (login as admin → toggle 7d/30d/90d → verify chart bar
  counts and aria-pressed state, plus API responses for each range)
  passes.

Notes / deviations:
- Had to (re)create the `app_opens` table in the dev DB and reset the
  seeded admin password hash to run the e2e test; both were preexisting
  environment drift unrelated to this task.
- Followed up with: custom date range, persisting last-used range.

Replit-Task-Id: 8066030b-b5c4-4b5c-a630-65616df5449e

lib/api-spec/openapi.yaml

@@ -730,6 +730,15 @@ paths:
       operationId: getAdminStats
       tags: [stats]
       summary: Get admin dashboard trend stats
+      parameters:
+        - in: query
+          name: range
+          required: false
+          schema:
+            type: string
+            enum: ["7d", "30d", "90d"]
+            default: "7d"
+          description: Time range for trend stats
       responses:
         "200":
           description: Admin stats
@@ -1337,9 +1346,14 @@ components:
     AdminStats:
       type: object
       properties:
-        newUsersLast7Days:
+        range:
+          type: string
+          enum: ["7d", "30d", "90d"]
+        rangeDays:
           type: integer
-        newUsersPrev7Days:
+        newUsersInRange:
+          type: integer
+        newUsersPrevRange:
           type: integer
         activeServices:
           type: integer
@@ -1369,9 +1383,9 @@ components:
             required:
               - date
               - count
-        appOpensLast7Days:
+        appOpensInRange:
           type: integer
-        appOpensPrev7Days:
+        appOpensPrevRange:
           type: integer
         servicesCreatedByDay:
           type: array
@@ -1385,16 +1399,18 @@ components:
             required:
               - date
               - count
-        servicesCreatedLast7Days:
+        servicesCreatedInRange:
           type: integer
       required:
-        - newUsersLast7Days
-        - newUsersPrev7Days
+        - range
+        - rangeDays
+        - newUsersInRange
+        - newUsersPrevRange
         - activeServices
         - inactiveServices
         - signupsByDay
         - appOpensByDay
-        - appOpensLast7Days
-        - appOpensPrev7Days
+        - appOpensInRange
+        - appOpensPrevRange
         - servicesCreatedByDay
-        - servicesCreatedLast7Days
+        - servicesCreatedInRange