fix(frontend): drop deprecated tsconfig baseUrl (RAN-11)

TypeScript 5.5 deprecated baseUrl (TS5101). Removing it makes the
local `mvn test` / `npm run build` green on Node >= 22 without a
silent `ignoreDeprecations` suppression. The `paths` mapping is
retained and resolves relative to tsconfig.json under
`moduleResolution: "bundler"`, and Vite's `resolve.alias` already
handles `@/*` at bundle time.

Verified: `npm run build` (tsc -b && vite build) on Node v24.15.0.

Co-Authored-By: Paperclip <noreply@paperclip.ing>

Author: aksOps

src/main/frontend/tsconfig.json

@@ -17,7 +17,6 @@
     "noImplicitReturns": true,
     "noFallthroughCasesInSwitch": true,
     "forceConsistentCasingInFileNames": true,
-    "baseUrl": ".",
     "paths": {
       "@/*": ["./src/*"]
     }