Fix install and deploy commands (#19481)

- disable publish with existing version
- disable installation of app version already installed

---------

Co-authored-by: cubic-dev-ai[bot] <191113872+cubic-dev-ai[bot]@users.noreply.github.com>

packages/twenty-docs/developers/extend/apps/publishing.mdx

@@ -66,12 +66,18 @@ The share link uses the server's base URL (without any workspace subdomain) so i
 
 ### Version management
 
+When updating an already deployed tarball app, the server requires the `version` in `package.json` to be **strictly higher** (per [semver](https://semver.org) ordering) than the currently deployed version. Re-deploying the same version, or pushing a lower one, is rejected before the tarball is stored — you'll see a `VERSION_ALREADY_EXISTS` error from the CLI.
+
 To release an update:
 
-1. Bump the `version` field in your `package.json`
+1. Bump the `version` field in your `package.json` (e.g. `1.2.3` → `1.2.4`, `1.3.0`, or `2.0.0`)
 2. Run `yarn twenty deploy` (or `yarn twenty deploy --remote production`)
 3. Workspaces that have the app installed will see the upgrade available in their settings
 
+<Note>
+Pre-release tags work as expected: bumping `1.0.0-rc.1` → `1.0.0-rc.2` is allowed, and a final release like `1.0.0` is correctly recognized as higher than `1.0.0-rc.5`. The version in `package.json` must itself be a valid semver string.
+</Note>
+
 {/* TODO: add screenshot of the Upgrade button */}
 
 ## Publishing to npm
@@ -189,3 +195,12 @@ You can also install apps from the command line:
 ```bash filename="Terminal"
 yarn twenty install
 ```
+
+<Note>
+The server enforces semver versioning on install, mirroring the rules on deploy:
+
+- Installing the same version that is already installed in your workspace is rejected with an `APP_ALREADY_INSTALLED` error.
+- Installing a lower version than the one currently installed is rejected with a `CANNOT_DOWNGRADE_APPLICATION` error.
+
+To install a newer version, deploy or publish it first, then re-run `yarn twenty install`.
+</Note>