feat: implement Firebase multi-site hosting configuration

- Update firebase.json to support three hosting targets (dev, qa, prod)
- Update .firebaserc to map targets to specific hosting sites
- Modify firebase-deployment.yml to deploy to target-specific sites
- Change FIREBASE_PROJECT_ID from secret to variable (addressing PR feedback)
- Use rainbowrelax.web.app for production (simpler URL)

Addresses PR comments:
- Project ID moved from secrets to variables
- Site URLs hardcoded in documentation and workflows
- Added multi-site architecture explanation

Author: jfugalde

.firebaserc

@@ -5,10 +5,16 @@
   "targets": {
     "rainbowrelax-46f61": {
       "hosting": {
-        "dev": ["rainbowrelax-dev"],
-        "qa": ["rainbowrelax-qa"],
-        "prod": ["rainbowrelax-prod"]
+        "dev": [
+          "rainbowrelax-dev"
+        ],
+        "qa": [
+          "rainbowrelax-qa"
+        ],
+        "prod": [
+          "rainbowrelax"
+        ]
       }
     }
   }
-}
+}

.github/workflows/firebase-deployment.yml

@@ -4,7 +4,7 @@ on:
   workflow_call:
     inputs:
       environment:
-        description: 'Deployment environment (develop, qa, live)'
+        description: "Deployment environment (develop, qa, live)"
         required: true
         type: string
 
@@ -15,16 +15,16 @@ jobs:
   build-and-deploy:
     runs-on: ubuntu-latest
     environment: ${{ inputs.environment }}
-    
+
     steps:
       - name: Checkout Repository
         uses: actions/checkout@v4
 
       - name: Setup Node.js
         uses: actions/setup-node@v4
         with:
-          node-version: '20'
-          cache: 'npm'
+          node-version: "20"
+          cache: "npm"
 
       - name: Install Dependencies
         run: npm ci
@@ -62,7 +62,7 @@ jobs:
           elif [ "${{ inputs.environment }}" = "qa" ]; then
             echo "url=https://rainbowrelax-qa.web.app" >> $GITHUB_OUTPUT
           elif [ "${{ inputs.environment }}" = "live" ]; then
-            echo "url=https://rainbowrelax-prod.web.app" >> $GITHUB_OUTPUT
+            echo "url=https://rainbowrelax.web.app" >> $GITHUB_OUTPUT
           fi
 
       - name: Comment Deployment URL
@@ -75,4 +75,4 @@ jobs:
               owner: context.repo.owner,
               repo: context.repo.repo,
               body: `🚀 **${{ inputs.environment }} Deployment Complete!**\n\n**URL:** ${{ steps.deployment-url.outputs.url }}\n\n**Environment:** ${{ inputs.environment }}\n**Commit:** ${{ github.sha }}`
-            })
+            })