feat(headroom): activate/uninstall extras + fix interpreter detection

- find interpreter next to headroom binary so extras/version read correctly
- add on/off toggle to activate [code]/[ml] via proxy restart
- add uninstall action + live install log progress + ~1GB confirm modal

src/app/api/headroom/extras/route.js

@@ -1,11 +1,15 @@
 import { NextResponse } from "next/server";
 import { findPython310, getInstalledHeadroomExtras, HEADROOM_COMPRESSION_EXTRAS } from "@/lib/headroom/detect";
-import { installHeadroomExtras } from "@/lib/headroom/process";
+import { installHeadroomExtras, uninstallHeadroomExtras, getInstallLogTail } from "@/lib/headroom/process";
 
 export const dynamic = "force-dynamic";
 
-export async function GET() {
+export async function GET(req) {
   try {
+    // `?log=1` returns the live install/uninstall log tail for progress polling.
+    if (new URL(req.url).searchParams.get("log") === "1") {
+      return NextResponse.json({ log: getInstallLogTail() });
+    }
     const python = findPython310();
     const status = getInstalledHeadroomExtras(python);
     return NextResponse.json({
@@ -28,3 +32,15 @@ export async function POST(req) {
     return NextResponse.json({ error: error.message, code: error.code || null }, { status });
   }
 }
+
+export async function DELETE(req) {
+  try {
+    const body = await req.json().catch(() => ({}));
+    const requested = Array.isArray(body?.extras) ? body.extras : [];
+    const result = await uninstallHeadroomExtras(requested);
+    return NextResponse.json(result);
+  } catch (error) {
+    const status = error.code === "NO_PYTHON" || error.code === "INVALID_EXTRAS" ? 400 : 500;
+    return NextResponse.json({ error: error.message, code: error.code || null }, { status });
+  }
+}