Include gitignored OpenAPI specs as Turbo inputs to fix stale client generation (#856)

### Summary & Motivation

Fix stale frontend API client generation caused by Turbo not detecting
changes to gitignored OpenAPI spec files. After the recent removal of
`*.Api.json` files from version control, Turbo's cache no longer
detected when the backend regenerated these specs, causing `dev:setup`
and `build` tasks to skip re-running `openapi-typescript`. This resulted
in the frontend loading a stale `api.generated.d.ts` with missing types
and API paths.

- Add `shared/lib/api/*.Api.json` as explicit Turbo inputs alongside
`$TURBO_DEFAULT$` for both `build` and `dev:setup` tasks, so Turbo
includes the gitignored OpenAPI specs in its cache hash and invalidates
correctly when the backend regenerates them

### Checklist

- [x] I have added tests, or done manual regression tests
- [x] I have updated the documentation, if necessary

Author: tjementum

application/turbo.json

@@ -3,6 +3,7 @@
   "globalEnv": ["CERTIFICATE_PASSWORD"],
   "tasks": {
     "build": {
+      "inputs": ["$TURBO_DEFAULT$", "shared/lib/api/*.Api.json"],
       "outputs": ["dist/**", "tests/test-results/**"],
       "dependsOn": ["^build"]
     },
@@ -18,6 +19,7 @@
     },
     "dev:setup": {
       "dependsOn": ["^dev:setup"],
+      "inputs": ["$TURBO_DEFAULT$", "shared/lib/api/*.Api.json"],
       "outputs": ["dist/**"]
     },
     "lint": {