[development] pop up an OS notification when a development build finishes

### What is this about?

I often will run `yarn start` and then while waiting, get distracted by something else, and many minutes will go by before i realize the build finished. Same goes for when later making edits and waiting for the update to be completed.

We should use OS notifications / any way of giving an indication that the build is completed (literally anything would be better than waiting for it to say 'primary' lol)

### Scenario

_No response_

### Design

_No response_

### Technical Details

_No response_

### Threat Modeling Framework

_No response_

### Acceptance Criteria

_No response_

### Stakeholder review needed before the work gets merged

- [ ] Engineering (needed in most cases)
- [ ] Design
- [ ] Product
- [ ] QA (automation tests are required to pass before merging PRs but not all changes are covered by automation tests - please review if QA is needed beyond automation tests)
- [ ] Security
- [ ] Legal
- [ ] Marketing
- [ ] Management (please specify)
- [ ] Other (please specify)

### References

_No response_

Start by running `yarn start` and trace the development build completion path in the TypeScript project. Determine where both the initial build and later edit updates finish, then verify that an OS notification or another visible indication appears for each completion.

Written by the indexing model from the issue text.