Bump version to 0.3.19 and update API endpoint

Update version from 0.3.18 to 0.3.19 in Cargo.toml, package-lock.json, and version.txt.

Also update the API endpoint in pmoparadise/src/client.rs from `/get_block` to `/play` and remove the `peer` property from several dependencies in package-lock.json.

Additionally, update the ARCHITECTURE.md documentation to reflect the change in API endpoint.

pmoapp/webapp/package-lock.json

@@ -859,7 +859,6 @@
       "integrity": "sha512-1N9SBnWYOJTrNZCdh/yJE+t910Y128BoyY+zBLWhL3r0TYzlTmFdXrPwHL9DyFZmlEXNQQolTZh3KHV31QDhyA==",
       "dev": true,
       "license": "MIT",
-      "peer": true,
       "dependencies": {
         "undici-types": "~6.21.0"
       }
@@ -1383,7 +1382,6 @@
       "integrity": "sha512-5gTmgEY/sqK6gFXLIsQNH19lWb4ebPDLA4SdLP7dsWkIXHWlG66oPuVvXSGFPppYZz8ZDZq0dYYrbHfBCVUb1Q==",
       "dev": true,
       "license": "MIT",
-      "peer": true,
       "engines": {
         "node": ">=12"
       },
@@ -1550,7 +1548,6 @@
       "integrity": "sha512-p1diW6TqL9L07nNxvRMM7hMMw4c5XOo/1ibL4aAIGmSAt9slTE1Xgw5KWuof2uTOvCg9BY7ZRi+GaF+7sfgPeQ==",
       "devOptional": true,
       "license": "Apache-2.0",
-      "peer": true,
       "bin": {
         "tsc": "bin/tsc",
         "tsserver": "bin/tsserver"
@@ -1572,7 +1569,6 @@
       "integrity": "sha512-VbA8ScMvAISJNJVbRDTJdCwqQoAareR/wutevKanhR2/1EkoXVZVkkORaYm/tNVCjP/UDTKtcw3bAkwOUdedmA==",
       "dev": true,
       "license": "MIT",
-      "peer": true,
       "dependencies": {
         "esbuild": "^0.25.0",
         "fdir": "^6.5.0",
@@ -1654,7 +1650,6 @@
       "resolved": "https://registry.npmjs.org/vue/-/vue-3.5.22.tgz",
       "integrity": "sha512-toaZjQ3a/G/mYaLSbV+QsQhIdMo9x5rrqIpYRObsJ6T/J+RyCSFwN2LHNVH9v8uIcljDNa3QzPVdv3Y6b9hAJQ==",
       "license": "MIT",
-      "peer": true,
       "dependencies": {
         "@vue/compiler-dom": "3.5.22",
         "@vue/compiler-sfc": "3.5.22",