future-plans: read-only public mode via runtime flag

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

future-plans.md

@@ -148,6 +148,19 @@ This would allow:
 - Unit conversion on query (e.g. `temp > 200K` matching a stored `-73°C`)
 - Catching unit mismatches at entry time
 
+## Deployment
+
+### Read-only public mode
+A runtime flag (e.g. `READ_ONLY=1`) that starts the server in a read-only mode
+suitable for public-facing deployment:
+- All write API endpoints disabled (POST/PUT/DELETE return 403)
+- UI hides all edit controls, dialogs, and maintenance actions
+- Data served directly from the same `data/` directory
+
+This allows a simple deployment workflow: rsync the `data/` directory from the
+private instance to a public server running in read-only mode. No database sync,
+no separate export step.
+
 ## Search & views
 
 ### Custom search views