rename OTAMan → SIMple (v2.3.0)

- package pysim_otaman_server → pysim_simple_server; distribution and
  console script pysim-otaman-server → pysim-simple-server
- PWA branding SIMple: title, header, manifest, help EN/RU, GitHub links
- localStorage keys otaman_* → simple_* (clean break, no migration)
- export filenames simple-cards.json / simple-custom-files.json
- service worker cache simple-v189
- README/docs/setup/start scripts updated; no 'otaman' left in the tree

frontend/package-lock.json

@@ -1,11 +1,11 @@
 {
-  "name": "otaman",
+  "name": "simple",
   "version": "1.0.0",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
-      "name": "otaman",
+      "name": "simple",
       "version": "1.0.0",
       "dependencies": {
         "aes-js": "^3.1.2",