chore(oss): audit the server package and resync the SDK mirrors

Split the 657-line operation service into eor, submit, and verify
modules, add the AGENT_REVOKED and KEY_RETIRED codes the Backend already
emits, and condense every multi-line comment. Mirror Node, Python, and
Go at 2.1.0 with the deep-health 503, non-idempotent retry, rotation
grace, and path-encoding fixes. Document which routes and response
fields the self-hosted server does not provide.

Claude-Session: https://claude.ai/code/session_01Agoc9bRVE9KL7mmWtey9Vq

sdks/node/package-lock.json

@@ -1,12 +1,12 @@
 {
   "name": "@elydora/sdk",
-  "version": "2.0.1",
+  "version": "2.1.0",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "@elydora/sdk",
-      "version": "2.0.1",
+      "version": "2.1.0",
       "license": "MIT",
       "dependencies": {
         "@decimalturn/toml-patch": "^2.0.0",