feat(frontend): feature flag for the Swap feature (#3906)

# Motivation

A feature flag for the Swap feature. 

Note: `feat/swap` will be a base branch for this functionality until the
whole feature is ready to go to staging.

.env.example

@@ -15,3 +15,4 @@ VITE_AUTH_DERIVATION_ORIGIN=
 VITE_ONRAMPER_API_KEY_DEV=pk_test_
 VITE_ONRAMPER_API_KEY_PROD=pk_prod_
 VITE_BTC_TO_CKBTC_EXCHANGE_ENABLED=
+VITE_SWAP_ACTION_ENABLED=

.github/workflows/deploy-to-environment.yml

@@ -104,6 +104,7 @@ jobs:
             echo "VITE_POUH_ENABLED=${{ secrets.VITE_POUH_ENABLED_STAGING }}" >> $GITHUB_ENV
             echo "VITE_AUTH_DERIVATION_ORIGIN=${{ secrets.VITE_AUTH_DERIVATION_ORIGIN_STAGING }}" >> $GITHUB_ENV
             echo "VITE_BTC_TO_CKBTC_EXCHANGE_ENABLED=${{ secrets.VITE_BTC_TO_CKBTC_EXCHANGE_ENABLED_STAGING }}" >> $GITHUB_ENV
+            echo "VITE_SWAP_ACTION_ENABLED=${{ secrets.VITE_SWAP_ACTION_ENABLED_STAGING }}" >> $GITHUB_ENV
             echo "VITE_ONRAMPER_API_KEY_DEV=${{ secrets.VITE_ONRAMPER_API_KEY_DEV_STAGING }}" >> $GITHUB_ENV
             echo "VITE_ONRAMPER_API_KEY_PROD=${{ secrets.VITE_ONRAMPER_API_KEY_PROD_STAGING }}" >> $GITHUB_ENV
             if [[ "$NETWORK" == "staging" ]]; then
@@ -135,6 +136,7 @@ jobs:
             echo "VITE_AUTH_ALTERNATIVE_ORIGINS=${{ secrets.VITE_AUTH_ALTERNATIVE_ORIGINS_BETA }}" >> $GITHUB_ENV
             echo "VITE_AUTH_DERIVATION_ORIGIN=${{ secrets.VITE_AUTH_DERIVATION_ORIGIN_BETA }}" >> $GITHUB_ENV
             echo "VITE_BTC_TO_CKBTC_EXCHANGE_ENABLED=${{ secrets.VITE_BTC_TO_CKBTC_EXCHANGE_ENABLED_BETA }}" >> $GITHUB_ENV
+            echo "VITE_SWAP_ACTION_ENABLED=${{ secrets.VITE_SWAP_ACTION_ENABLED_BETA }}" >> $GITHUB_ENV
             echo "VITE_ONRAMPER_API_KEY_DEV=${{ secrets.VITE_ONRAMPER_API_KEY_DEV_BETA }}" >> $GITHUB_ENV
             echo "VITE_ONRAMPER_API_KEY_PROD=${{ secrets.VITE_ONRAMPER_API_KEY_PROD_BETA }}" >> $GITHUB_ENV
             {

src/frontend/src/env/actions.env.ts

@@ -0,0 +1,3 @@
+// TODO: to be removed when the feature is fully implemented
+export const SWAP_ACTION_ENABLED =
+	JSON.parse(import.meta.env.VITE_SWAP_ACTION_ENABLED ?? false) === true;