feat: multi-format viewer (Text/Hex/JSON/Binary/Gzip/Deflate/Brotli)

- New format.ts: decodeValue + detectFormat using Node.js zlib
- IPC: redis:decodeValue, redis:detectFormat
- StringEditor: format selector dropdown with auto-detect
- Monaco editor shows decoded value, read-only for compressed formats
- Auto-detect: JSON, Gzip (1f 8b), Deflate (78 xx), non-printable → Hex
- i18n keys for all formats (zh-CN + en)

electron/main/redis/format.ts

@@ -0,0 +1,46 @@
+// electron/main/redis/format.ts
+// 值格式转换（解压/编码）
+import { gunzipSync, inflateSync, brotliDecompressSync } from 'zlib'
+
+export type FormatType = 'text' | 'hex' | 'json' | 'binary' | 'gzip' | 'deflate' | 'brotli' | 'deflateRaw'
+
+export function decodeValue(value: string, format: FormatType): string {
+  const buf = Buffer.from(value, 'utf-8')
+  switch (format) {
+    case 'hex':
+      return buf.toString('hex').match(/.{1,2}/g)?.join(' ') ?? ''
+    case 'binary':
+      return buf.toString('binary')
+    case 'json':
+      try {
+        return JSON.stringify(JSON.parse(value), null, 2)
+      } catch {
+        return value
+      }
+    case 'gzip':
+      try { return gunzipSync(buf).toString('utf-8') } catch { return '[Gzip decode failed]' }
+    case 'deflate':
+      try { return inflateSync(buf).toString('utf-8') } catch { return '[Deflate decode failed]' }
+    case 'brotli':
+      try { return brotliDecompressSync(buf).toString('utf-8') } catch { return '[Brotli decode failed]' }
+    case 'deflateRaw':
+      try { return inflateSync(buf).toString('utf-8') } catch { return '[DeflateRaw decode failed]' }
+    default:
+      return value
+  }
+}
+
+export function detectFormat(value: string): FormatType {
+  if (!value) return 'text'
+  // JSON
+  try { JSON.parse(value); return 'json' } catch { /* not json */ }
+  // Gzip magic: 1f 8b
+  if (value.charCodeAt(0) === 0x1f && value.charCodeAt(1) === 0x8b) return 'gzip'
+  // Brotli magic (less reliable, check common patterns)
+  // Deflate (zlib) magic: 78 01/9c/da
+  if (value.charCodeAt(0) === 0x78 && [0x01, 0x9c, 0xda, 0x5e].includes(value.charCodeAt(1))) return 'deflate'
+  // Check for non-printable characters → binary/hex
+  const hasNonPrintable = /[\x00-\x08\x0e-\x1f]/.test(value.substring(0, 100))
+  if (hasNonPrintable) return 'hex'
+  return 'text'
+}