normalize project structure: src/client + src/server + src/shared, standardize biome to lineWidth 80

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

biome.json

@@ -1,7 +1,7 @@
 {
 	"$schema": "https://biomejs.dev/schemas/1.9.0/schema.json",
 	"files": {
-		"ignore": ["src/routeTree.gen.ts"]
+		"ignore": ["src/client/routeTree.gen.ts", "drizzle/"]
 	},
 	"organizeImports": {
 		"enabled": true
@@ -9,7 +9,7 @@
 	"formatter": {
 		"enabled": true,
 		"indentStyle": "tab",
-		"lineWidth": 100
+		"lineWidth": 80
 	},
 	"linter": {
 		"enabled": true,