fix(self-host): drop bun install from chart CI, remove air-gapped and backup docs

The scheduler-parity check pulled a full dependency install into the
chart-validation job, which fails building isolated-vm on that runner.
Rewritten to use only node builtins so the job installs nothing.

Also removes the air-gapped and backup/restore pages, and stops pinning a
concrete release in the docs so the examples do not go stale each release.

Author: waleedlatif1

.github/workflows/helm.yml

@@ -37,11 +37,9 @@ jobs:
         with:
           bun-version: 1.3.13
 
-      - name: Install dependencies
-        run: bun install --frozen-lockfile
-
       # Docker Compose and Kubernetes must run the same background jobs on the
-      # same schedules; this fails the build if the two drift apart.
+      # same schedules; this fails the build if the two drift apart. The script
+      # imports only node builtins, so this job installs no dependencies.
       - name: Scheduler parity (docker/crontab vs helm cronjobs)
         run: bun run scripts/check-cron-parity.ts
 

apps/docs/content/docs/en/platform/self-hosting/air-gapped.mdx

@@ -73,7 +73,7 @@ Three places once the deployment is configured for production. Everything else i
 </Callout>
 
 <Callout type="error">
-  `ENCRYPTION_KEY` is not recoverable and not derivable. It encrypts workspace and personal environment variables, stored provider API keys, MCP OAuth credentials, and deployment/chat secrets at rest — a database restore paired with a *different* key yields a working app in which none of that can be decrypted. Back it up separately from the database, and never rotate it casually. See [Backup & Restore](/platform/self-hosting/backup-restore).
+  `ENCRYPTION_KEY` is not recoverable and not derivable. It encrypts workspace and personal environment variables, stored provider API keys, MCP OAuth credentials, and deployment/chat secrets at rest — a database restore paired with a *different* key yields a working app in which none of that can be decrypted. Back it up separately from the database, and never rotate it casually.
 </Callout>
 
 Redis is a cache and message bus. Losing it drops in-flight live updates; it does not lose committed data.