Saved Jobs: navigation, placeholder screen, and unit tests

[kassandrabeas5]

Issue addressed: Implements Job View Full Detail #24 and Save Job Feature #23 (sub-issues of Job Listing page #13).

Tests written & passed:

• jobs.test.tsx → verifies “Saved Jobs” button navigates to /savedJobs.
• jobs.save.test.tsx → verifies pressing “Save Job” calls the add function.
• savedJobs.test.tsx (smoke) → verifies Saved Jobs screen renders the title/placeholders.
  All tests pass (npm test → screenshot included for coverage requirement).

Changes made:
jobs.tsx

• Added navigation: “Saved Jobs” button routes to /savedJobs.
• Hooked up Save Job button to add jobs into a simple store/context.

savedJobs.tsx
-Implemented dark-themed placeholder UI.

• Displays saved jobs (placeholder for now)

tests

• Added unit tests for navigation, saving, and placeholders.

_layout.tsx
-Wrapped app in SavedJobsProvider to share state across screens.

[AchsahJojo]

looks good to go, the style is very clear and modern. But start adding in API implementation asap