Rename quack to quak

German for 'quack', matching the Ente (German for 'duck') naming. All
references updated: package name, CLI binary, X-Client-Package header,
test descriptions, temp dir prefixes, README, Makefile docker tag.

package.json

@@ -1,19 +1,19 @@
 {
-    "name": "quack",
+    "name": "quak",
     "version": "0.0.0",
     "description": "TypeScript client library and CLI for the Ente end-to-end encrypted photo service",
     "license": "WTFPL",
     "author": "@sneak <https://sneak.berlin>",
-    "homepage": "https://git.eeqj.de/sneak/quack",
+    "homepage": "https://git.eeqj.de/sneak/quak",
     "repository": {
         "type": "git",
-        "url": "https://git.eeqj.de/sneak/quack.git"
+        "url": "https://git.eeqj.de/sneak/quak.git"
     },
     "type": "module",
     "main": "./dist/index.js",
     "types": "./dist/index.d.ts",
     "bin": {
-        "quack": "./dist/bin/quack.js"
+        "quak": "./dist/bin/quak.js"
     },
     "files": [
         "dist/",