Add realtime loopback STT prototype

src/config.ts

@@ -0,0 +1,34 @@
+import { config as loadDotenv } from "dotenv";
+import { z } from "zod";
+
+loadDotenv();
+
+const emptyToUndefined = z.preprocess((value) => {
+  if (typeof value !== "string") {
+    return value;
+  }
+  const trimmed = value.trim();
+  return trimmed.length === 0 ? undefined : trimmed;
+}, z.string().min(1).optional());
+
+const envSchema = z.object({
+  LOCAL_AI_VENV_PATH: z.string().min(1).default(".local-ai/.venv"),
+  LOCAL_AI_PYTHON: emptyToUndefined,
+  AUDIO_SOURCE: emptyToUndefined,
+  WHISPER_MODEL: z.string().min(1).default("large-v3-turbo"),
+  WHISPER_LANGUAGE: z.string().min(1).default("ko"),
+  WHISPER_DEVICE: z.enum(["auto", "cuda", "cpu"]).default("auto"),
+  WHISPER_COMPUTE_TYPE: z.string().min(1).default("auto"),
+  WHISPER_BEAM_SIZE: z.coerce.number().int().min(1).max(8).default(1),
+  DEBUG_TRANSCRIPTS: z
+    .string()
+    .optional()
+    .transform((value) => value === "true"),
+  LOG_LEVEL: z.enum(["debug", "info", "warn", "error"]).default("info"),
+});
+
+export type AppConfig = z.infer<typeof envSchema>;
+
+export function loadConfig(): AppConfig {
+  return envSchema.parse(process.env);
+}