fix(repo): run turbo via yarn exec for root scripts (#911)

Root build and test scripts invoked `turbo` as a bare binary, which only
works when `node_modules/.bin` is on the shell PATH.

Cursor's agent sandbox (and similar restricted runners) often use a
minimal PATH without that directory, producing "command not found:
turbo" even though turbo is installed.

Use `yarn exec turbo` so Yarn resolves and runs the workspace dependency
without relying on PATH.

<!-- CURSOR_SUMMARY -->
---

> [!NOTE]
> **Low Risk**
> Low risk: only adjusts root `package.json` scripts to invoke Turbo via
Yarn, affecting how builds/tests are launched but not
application/runtime logic.
> 
> **Overview**
> Switches root scripts to run Turbo via Yarn resolution instead of
relying on the `turbo` binary being on `PATH`.
> 
> Updates `build`, `test:dev`, and `test:dev:quiet` to use `yarn exec
turbo run ...`, improving compatibility in environments with restricted
`PATH` settings (e.g., CI/sandboxes).
> 
> <sup>Written by [Cursor
Bugbot](https://cursor.com/dashboard?tab=bugbot) for commit
c21c392. This will update automatically
on new commits. Configure
[here](https://cursor.com/dashboard?tab=bugbot).</sup>
<!-- /CURSOR_SUMMARY -->

Author: grypez

package.json

@@ -12,7 +12,7 @@
     "packages/*"
   ],
   "scripts": {
-    "build": "turbo run build",
+    "build": "yarn exec turbo run build",
     "build:clean": "yarn clean && yarn build",
     "build:docs": "yarn workspaces foreach --all --exclude @ocap/monorepo --exclude @ocap/extension --parallel --interlaced --verbose run build:docs",
     "changelog:update": "yarn workspaces foreach --all --no-private --parallel --interlaced --verbose run changelog:update",
@@ -29,8 +29,8 @@
     "prepack": "./scripts/prepack.sh",
     "rebuild:native": "./scripts/rebuild-native.sh",
     "test": "vitest run",
-    "test:dev": "turbo run test:dev",
-    "test:dev:quiet": "turbo run test:dev:quiet --output-logs=errors-only",
+    "test:dev": "yarn exec turbo run test:dev",
+    "test:dev:quiet": "yarn exec turbo run test:dev:quiet --output-logs=errors-only",
     "test:e2e": "yarn workspaces foreach --all run test:e2e",
     "test:e2e:ci": "yarn workspaces foreach --all run test:e2e:ci",
     "test:e2e:local": "yarn workspaces foreach --all run test:e2e:local",