Fix API URL: use bun script for reliable placeholder replacement

Dockerfile

@@ -14,15 +14,35 @@ RUN bun install --frozen-lockfile
 # Build static files (output lands in /app/frontend/dist)
 COPY frontend/ ./frontend/
 
-# Build with a unique placeholder for VITE_API_URL. Vite statically replaces
-# import.meta.env.VITE_API_URL with this literal string at compile time.
-# After build, we swap the placeholder for `window.location.origin` so the
-# frontend dynamically resolves the API base from the browser's current URL.
-# This makes it work on any deployment (HF Spaces, self-hosted Docker, etc.)
-# without hardcoding hosts.
+# Write a patcher script that replaces the API URL placeholder with
+# window.location.origin in the compiled JS output. Using bun to run
+# the script ensures it works on Alpine (no sed/find compatibility issues).
+RUN cat > /tmp/patch_api.mjs << 'PATCHEOF'
+import { readdirSync, statSync, readFileSync, writeFileSync } from "fs";
+import { join } from "path";
+
+function walk(dir) {
+  for (const f of readdirSync(dir)) {
+    const p = join(dir, f);
+    if (statSync(p).isDirectory()) walk(p);
+    else if (f.endsWith(".js")) {
+      let c = readFileSync(p, "utf8");
+      if (c.includes("__OMNIVOICE_RUNTIME_ORIGIN__")) {
+        c = c.replaceAll('"__OMNIVOICE_RUNTIME_ORIGIN__"', "window.location.origin");
+        c = c.replaceAll("'__OMNIVOICE_RUNTIME_ORIGIN__'", "window.location.origin");
+        c = c.replaceAll("__OMNIVOICE_RUNTIME_ORIGIN__", "window.location.origin");
+        writeFileSync(p, c);
+        console.log("Patched:", p);
+      }
+    }
+  }
+}
+walk("/app/frontend/dist");
+PATCHEOF
+
+# Build with placeholder, then patch compiled JS to use window.location.origin
 RUN VITE_API_URL="__OMNIVOICE_RUNTIME_ORIGIN__" bun run --cwd frontend build && \
-    find /app/frontend/dist -name '*.js' -exec \
-      sed -i 's|"__OMNIVOICE_RUNTIME_ORIGIN__"|window.location.origin|g' {} +
+    bun /tmp/patch_api.mjs
 
 # ==========================================
 # Runtime Stage: Python & PyTorch Backend