Untrack .env and .env.testcopy

Both are already listed in .gitignore but were committed in 92f44a2, so they
stayed tracked. .env holds a live DeepL API key. The files remain on disk for
local runs; only the tracking is removed.

This drops them from HEAD, not from history — 92f44a2 still contains the key
and is already on the remote, so the key must be rotated regardless.

Co-Authored-By: Claude <noreply@anthropic.com>

.env

@@ -1,9 +0,0 @@
-# Fill in your DeepL Growth API key below, then run: node server.js
-# This file stays on your machine and is read only by server.js.
-
-DEEPL_API_KEY=02a9299f-9f72-4c21-aa7c-788a19270409:fx
-
-#fd74146f-001c-44f9-ae9f-96d45d7f1922:fx
-
-# Optional: change the local port (default 3000)
-# PORT=3000

.env.testcopy

@@ -1,2 +0,0 @@
-# Not used by the app — leftover from testing. Safe to delete.
-# Configure your key in ".env" instead (see .env.example).