Design a Test Strategy & Improve Coverage

Background: Native [platform] app, [SwiftUI / Compose]. Current testing
state: [none / some unit tests / ad hoc]. Architecture: [your choice].
Team size: [solo / team]. 

Use case: Define a pragmatic test strategy—what to test, at which level,
and what to skip—so effort goes where it pays off.

Implementation details:
- Apply the test pyramid to mobile: many fast unit tests (logic/view
  models), fewer integration tests (repository + data), few UI tests
  (critical flows)
- Identify what's high-value to test (business logic, data mapping, sync,
  edge cases) vs low-value (trivial views, framework behavior)
- A realistic coverage target and what "good coverage" means here
- Where to add the first tests for the most risk reduction
- How tests will run in CI (sets up Section 11) and how fast they must be

Deliverable: A test strategy document: the pyramid breakdown for this
app, a prioritized list of what to test first, a sensible coverage
target, what to deliberately not test, and the path to running it all in
CI.