feat(#27): Set up consola logger, make use of log levels in backend and frontend

legalconsenthub/shared/utils/logger.ts

@@ -0,0 +1,48 @@
+import { createConsola } from 'consola'
+import type { ConsolaInstance } from 'consola'
+
+export type AppLogLevel = 'silent' | 'error' | 'warn' | 'info' | 'debug' | 'trace' | 'verbose' | 'log'
+
+export function createLogger(options: { level?: string; tag?: string; fancy?: boolean } = {}): ConsolaInstance {
+  const level = resolveConsolaLevel(options.level)
+
+  const logger = createConsola({
+    level
+  })
+
+  return options.tag ? logger.withTag(options.tag) : logger
+}
+
+export function resolveConsolaLevel(level?: string): number {
+  const normalized = (level ?? '').toString().trim().toLowerCase()
+
+  // Consola levels (from docs):
+  // 0: Fatal and Error
+  // 1: Warnings
+  // 2: Normal logs
+  // 3: Informational logs
+  // 4: Debug logs
+  // 5: Trace logs
+  // -999: Silent
+  // +999: Verbose logs
+  switch (normalized as AppLogLevel) {
+    case 'silent':
+      return -999
+    case 'error':
+      return 0
+    case 'warn':
+      return 1
+    case 'log':
+      return 2
+    case 'info':
+      return 3
+    case 'debug':
+      return 4
+    case 'trace':
+      return 5
+    case 'verbose':
+      return 999
+    default:
+      return 3
+  }
+}