PMM-15326: Add the OM UI plugin

Four pages over pmm-managed's /v1/om: Overview, Services, Hosts and
Inventory. The plugin depends on @sep/api nowhere and reads PMM's own
origin, so nothing it does needs a SEP bearer.

Types are hand-written rather than generated, because OM is not in PMM's
checked-in OpenAPI client set.

The lockfile carries only this package's own importer block. The apps/pmm
entry lands with the package.json that declares the dependency.

Signed-off-by: Pawel Lebioda <pawel.lebioda@percona.com>

Author: plebioda

ui/packages/plugins/om/package.json

@@ -0,0 +1,49 @@
+{
+  "name": "@sep/plugins-om",
+  "version": "0.0.0",
+  "private": true,
+  "type": "module",
+  "main": "./src/index.ts",
+  "types": "./src/index.ts",
+  "scripts": {
+    "type-check": "tsc --noEmit",
+    "check-types": "tsc --noEmit",
+    "test": "vitest run",
+    "test:watch": "vitest",
+    "lint": "oxlint --config ../../../oxlintrc.json src",
+    "format": "oxfmt --write src"
+  },
+  "devDependencies": {
+    "@emotion/react": "^11.11.4",
+    "@emotion/styled": "^11.11.5",
+    "@mui/icons-material": "^7.3.7",
+    "@mui/material": "^7.3.7",
+    "@percona/percona-ui": "1.0.22",
+    "@tanstack/react-query": "^5.100.7",
+    "@testing-library/jest-dom": "^6.6.3",
+    "@testing-library/react": "^16.3.0",
+    "@testing-library/user-event": "^14.6.1",
+    "@types/react": "^19.1.0",
+    "@vitejs/plugin-react-swc": "^4.3.1",
+    "jsdom": "^29.1.1",
+    "material-react-table": "^3.2.1",
+    "notistack": "^3.0.0",
+    "react": "^19.1.0",
+    "react-dom": "^19.1.0",
+    "react-router-dom": "^7.14.0",
+    "typescript": "~6.0.3",
+    "vitest": "^4.0.0"
+  },
+  "peerDependencies": {
+    "@emotion/react": "^11.0.0",
+    "@emotion/styled": "^11.0.0",
+    "@mui/icons-material": "^7.3.7",
+    "@mui/material": "^7.3.7",
+    "@percona/percona-ui": "^1.0.15",
+    "@tanstack/react-query": "^5.75.0",
+    "material-react-table": "^3.2.1",
+    "notistack": "^3.0.0",
+    "react": "^19.0.0",
+    "react-router-dom": "^7.14.0"
+  }
+}