build(coolify): use SOURCE_COMMIT build arg for deploynotify

Coolify sets SOURCE_COMMIT automatically; consume it as the build arg
feeding the baked commit SHA instead of a manually-passed GIT_SHA.

.env.example

@@ -23,9 +23,10 @@ ADMIN_IDS=
 # Only the twentyq module needs this. Leave blank to disable that command.
 GEMINI_API_KEY=
 
-# GIT_SHA is injected at build time by Coolify for the deploynotify owner DM.
-# Leave unset for local `docker compose up` — deploynotify just stays silent.
-# GIT_SHA=
+# SOURCE_COMMIT is injected as a build arg by Coolify (it sets it automatically)
+# for the deploynotify owner DM. Leave unset for local `docker compose up` —
+# deploynotify just stays silent.
+# SOURCE_COMMIT=
 
 # ====================== Leave UNSET on self-host ==================
 # These are AWS-only. cmd/server reads secrets directly from the plain env
@@ -33,7 +34,6 @@ GEMINI_API_KEY=
 # credentials and bricks startup. Do NOT set any of them:
 #   TELEGRAM_BOT_TOKEN_PARAMETER_NAME
 #   TELEGRAM_WEBHOOK_SECRET_PARAMETER_NAME
-#   CRON_SHARED_SECRET_PARAMETER_NAME
 #   GEMINI_API_KEY_PARAMETER_NAME
 #   STOCK_INCOME_EVENTS_API_TOKEN_PARAMETER_NAME
 #   GOLD_VNAPP_API_KEY_PARAMETER_NAME
@@ -42,6 +42,5 @@ GEMINI_API_KEY=
 #   KV_PROVIDER          — auto-selects mongodb because MONGO_URL is set
 #   PORT                 — defaults to 8080 (internal health server)
 #   TELEGRAM_WEBHOOK_SECRET — long polling has no webhook
-#   CRON_SHARED_SECRET   — unset → /cron route 404s; the in-process scheduler is the trigger
 #   GOLD_VNAPP_API_KEY   — gold module auto-fetches + caches the key to Mongo
 #   STOCK/COIN/GOLD *_API_URL overrides — modules use their coded default providers