fix: Simple timeless icon, favicon, correct BatchStage enums

- Replace tech circuit icon with simple clean leaf silhouette
- Add favicon.png and link in index.html
- Install icon to all mipmap directories including ic_launcher_foreground
- Fix BatchStage enums: FLOWERING, VEGETATIVE, DRYING (not FLOWER/VEG/DRY)

backend/prisma/seed.ts

@@ -299,7 +299,7 @@ async function main() {
             status: 'ACTIVE',
             plantCount: 48,
             source: 'CLONE',
-            stage: 'FLOWER',
+            stage: 'FLOWERING',
             roomId: flowerRoom?.id
         },
         {
@@ -310,7 +310,7 @@ async function main() {
             status: 'HARVESTED',
             plantCount: 36,
             source: 'CLONE',
-            stage: 'DRY'
+            stage: 'DRYING'
         },
         {
             name: 'B-2026-01-GDP',
@@ -319,7 +319,7 @@ async function main() {
             status: 'ACTIVE',
             plantCount: 24,
             source: 'SEED',
-            stage: 'VEG',
+            stage: 'VEGETATIVE',
             roomId: vegRoom?.id
         }
     ];

frontend/index.html

@@ -14,6 +14,7 @@
 <meta name="apple-mobile-web-app-title" content="Veridian" />
 <link rel="manifest" href="/manifest.json" />
 <link rel="apple-touch-icon" href="/icons/icon-192.png" />
+<link rel="icon" type="image/png" href="/favicon.png" />
 <title>Veridian - Cultivation Platform</title>
 </head>