Task #589: Live build stamp + server start time in System Updates panel

Problem: After `git pull && docker compose up -d --build api` on the
Mac, the admin → System Updates panel kept showing the same version
(0.1.0-dev) and the same build (20260517.b5efd9eb) because both come
from version.json, a hand-edited file that nothing rewrites on every
build. No visible signal that a new image was actually running.

Two independent signals were added — neither needs editing version.json
by hand:

1) Auto-stamp version.json at Docker build time
   - docker/api-server.Dockerfile: new ARGs GIT_SHA and BUILD_DATE.
     A `node -e` step rewrites version.json's `build` field to
     `${YYYYMMDDTHHmm}.${sha}` (e.g. 20260518T1042.a34eb5f5). When
     the args are missing/"unknown", version.json is left untouched
     so plain `docker build` and Replit `pnpm dev` still work.
   - docker-compose.yml: api.build.args wires through GIT_SHA and
     BUILD_DATE with `${GIT_SHA:-unknown}` fallbacks.
   - scripts/redeploy.sh: exports GIT_SHA (git rev-parse --short HEAD)
     and BUILD_DATE (date -u +%Y-%m-%dT%H:%M:%SZ) before `docker
     compose build`, so the helper script just works.

2) startedAt timestamp from the API
   - artifacts/api-server/src/routes/system.ts: SERVER_STARTED_AT
     captured at module load (frozen for the process lifetime) and
     added to every branch of GET /system/version (not-configured,
     error, invalid-version, up-to-date, update-available, catch).
   - lib/api-spec/openapi.yaml: added `startedAt: date-time` to
     SystemVersionResponse (required). Regenerated api-client-react
     and api-zod via `pnpm --filter @workspace/api-spec run codegen`.

3) Admin UI surfacing both signals
   - artifacts/tx-os/src/pages/admin.tsx: new formatBuildStamp parses
     `YYYYMMDD[THHmm].sha` and renders a localized date next to the
     raw token. A new "Server started" line below the build number
     formats the boot timestamp via the existing formatChecked helper.
   - artifacts/tx-os/src/locales/{en,ar}.json: added
     admin.systemUpdates.serverStartedAt ("Server started" /
     "بدأ تشغيل الخادم").

4) Docs
   - replit.md: documented how to verify a real redeploy via the
     System Updates panel and the manual one-liner for `docker
     compose build` without the helper script.

Verified: codegen succeeds, API workflow restarted clean, Vite served
fine. Pre-existing typecheck errors in push.ts and font-settings are
unrelated and untouched.

Mac next steps:
  cd ~/Downloads/TX && git pull && ./scripts/redeploy.sh
Then open admin → System Updates: build line should show a new
`YYYYMMDDTHHmm.sha` stamp and "Server started" should reflect the
new boot time.

lib/api-client-react/src/generated/api.schemas.ts

@@ -33,6 +33,12 @@ export interface SystemVersionResponse {
   /** @nullable */
   checkedAt: string | null;
   configured: boolean;
+  /** ISO-8601 timestamp captured when the API process booted.
+Frozen for the lifetime of the process — used by the admin
+System Updates panel as visible proof that the container
+actually restarted (independent of build/version changes).
+ */
+  startedAt: string;
 }
 
 export interface ErrorResponse {

lib/api-spec/openapi.yaml

@@ -2977,6 +2977,14 @@ components:
           format: date-time
         configured:
           type: boolean
+        startedAt:
+          type: string
+          format: date-time
+          description: |
+            ISO-8601 timestamp captured when the API process booted.
+            Frozen for the lifetime of the process — used by the admin
+            System Updates panel as visible proof that the container
+            actually restarted (independent of build/version changes).
       required:
         - current
         - latest
@@ -2984,6 +2992,7 @@ components:
         - errorMessage
         - checkedAt
         - configured
+        - startedAt
 
     ErrorResponse:
       type: object

lib/api-zod/src/generated/api.ts

@@ -43,6 +43,11 @@ export const GetSystemVersionResponse = zod.object({
   errorMessage: zod.string().nullable(),
   checkedAt: zod.coerce.date().nullable(),
   configured: zod.boolean(),
+  startedAt: zod.coerce
+    .date()
+    .describe(
+      "ISO-8601 timestamp captured when the API process booted.\nFrozen for the lifetime of the process — used by the admin\nSystem Updates panel as visible proof that the container\nactually restarted (independent of build\/version changes).\n",
+    ),
 });
 
 /**