Write a Unit Test Plan from a Spec

Turn this feature spec into a practical unit test plan:

Feature name: [FEATURE]
Spec / acceptance criteria: [PASTE]
Language / framework: [STACK]
Critical paths: [LIST]
Known edge cases: [LIST]
Out of scope: [LIST]

Requirements:
1. List unit test cases grouped by happy path, edge case, and failure mode.
2. For each case, name inputs, expected result, and why it matters.
3. Call out cases that need mocks or fixtures.
4. Suggest file naming and describe blocks that match the stack.
5. Flag anything that belongs in integration tests instead.

Deliverables:
1. A unit test plan table.
2. Skeleton test titles ready to paste into the suite.
3. A short risk list of untested areas if time is short.