feat: add export-assets script for CDN asset extraction and update Dockerfiles

docs/docs.json

@@ -330,6 +330,7 @@
                   "self-hosting/guides/custom-certificates",
                   "self-hosting/guides/automated-bootstrapping",
                   "self-hosting/guides/production-hardening",
+                  "self-hosting/guides/cdn-caching",
                   "self-hosting/guides/monitoring-telemetry"
                 ]
               },

docs/self-hosting/guides/cdn-caching.mdx

@@ -0,0 +1,106 @@
+---
+title: "CDN Caching for Static Assets"
+description: "How to set up CDN caching to prevent version skew issues during deployments"
+---
+
+This guide explains a common issue with frontend asset caching during deployments and how to solve it using a CDN.
+
+## The Problem: Version Skew
+
+Modern frontend build tools like Vite generate content-hashed filenames for static assets (e.g., `main-abc123.js`). Each build produces unique filenames based on file contents. During deployments, this can cause a race condition:
+
+1. User loads `index.html` which references `main-abc123.js`
+2. New deployment replaces containers with a new build
+3. New containers only serve `main-xyz789.js` (new build)
+4. User's browser requests `main-abc123.js` from cached HTML
+5. Request returns **404** — the old asset no longer exists
+
+This results in broken pages, failed SPA navigation, and requires users to manually refresh.
+
+<Note>
+This is a documented limitation in Vite's official guidance: [Load Error Handling](https://vite.dev/guide/build#load-error-handling)
+</Note>
+
+### Current Behavior
+
+Infisical includes a built-in workaround that detects version mismatches and triggers a page reload. While functional, this introduces a noticeable delay for users during deployments.
+
+## The Solution: External Asset Storage
+
+The solution is to store static assets externally (e.g., S3, GCS, Azure Blob) and serve them through a CDN (e.g., CloudFront, Cloud CDN, Cloudflare). Assets are uploaded **before** container deployment, ensuring old versions remain available.
+
+### How It Works
+
+```mermaid
+flowchart LR
+    User[User Browser]
+    CDN[CDN]
+    S3[(Object Storage)]
+    App[Your Infrastructure]
+
+    User --> CDN
+    CDN -->|"/assets/*"| S3
+    CDN -->|"/* (default)"| App
+```
+
+The key points:
+
+- **Asset persistence**: Old assets remain available even after new deployments
+- **Deployment order**: Upload new assets before deploying new containers
+- **Long cache TTL**: Content-hashed files can be cached indefinitely (we recommend 30 days)
+- **Automatic cleanup**: Configure lifecycle rules to expire old assets after 30 days
+
+At Infisical, we use **CloudFront + S3** for this purpose, but you can use any CDN and object storage combination that fits your infrastructure.
+
+## Exporting Assets
+
+Infisical provides a built-in command to export frontend assets from the Docker image:
+
+```bash
+# Export as tar archive to stdout
+docker run --rm infisical/infisical npm run assets:export > assets.tar
+
+# Extract the archive
+tar -xf assets.tar
+ls assets/  # Content-hashed JS/CSS files
+```
+
+Or export directly to a mounted directory:
+
+```bash
+docker run --rm -v $(pwd)/cdn-assets:/output \
+  infisical/infisical npm run assets:export /output
+```
+
+### What Gets Exported
+
+The command exports the `/assets` directory containing:
+
+- JavaScript bundles (e.g., `main-abc123.js`, `chunk-def456.js`)
+- CSS files (e.g., `styles-789xyz.css`)
+- Other static assets with content hashes
+
+These files are safe to cache with long TTLs because their filenames change whenever the content changes.
+
+## Integration with Your Pipeline
+
+The general deployment flow should be:
+
+1. **Build** your new Docker image (or pull the official Infisical image)
+2. **Export** assets using `npm run assets:export`
+3. **Upload** assets to your object storage
+4. **Deploy** the new container version
+
+```bash
+# Example: Export and upload to S3
+docker run --rm infisical/infisical:$VERSION npm run assets:export > assets.tar
+tar -xf assets.tar
+aws s3 sync assets s3://your-bucket/assets --cache-control "public, max-age=2592000"
+
+# Then deploy your container
+```
+
+<Warning>
+Always upload assets **before** deploying the new container. This ensures the assets referenced by the new `index.html` exist before users can access them.
+</Warning>
+