test: add unit tests for wrapped year-summary utility functions (#2720)

[desireddymohithreddy0925]

Description

Resolves #2720

This PR adds comprehensive unit testing for the pure utility functions exported from src/lib/wrapped.ts using Vitest. It ensures predictable analytics generation for the year-in-review (Wrapped) functionality.

Changes Made

• Created test/wrapped.test.ts:
  • getYearRange: Checked past full year boundaries, current partial year bounds, and leap years.
  • calculateLongestStreak: Mocked @/lib/streak to confirm empty cases, single active days, and multiple active days.
  • getMostProductiveMonth: Verified single highest month, uniform contributions, and tie-breaking behavior (index 0).
  • getMostContributedRepo: Checked empty commit arrays, single repos, and correctly ranked multiple repositories.
  • getPeakCodingHour: Validated empty/invalid datasets, single hour entries, tie-breaks via index, and correctly formatted 12-hour AM/PM string formats.
  • calculateLanguagePercentages: Ensured single/multiple languages sort by bytes descending, respects limits, and guards against zero total bytes gracefully.
  • calculatePersonality: Guaranteed deterministic output shapes and emojis across all identities: Weekend Warrior, Night Architect, Sprint Builder, Silent Architect, and Consistency Monk.

Acceptance Criteria

• Mocked the @/lib/streak dependency successfully for calculateLongestStreak.
• All exported wrapped utility functions are comprehensively covered by edge-case tested scenarios.
• The module now achieves 100% test coverage.
• All 31 tests run successfully and deterministically with vitest.

[github-actions]

GSSoC Label Checklist 🏷️

@Umbrella-io — please apply the appropriate labels before merging:

Difficulty (pick one):

• level:beginner — 20 pts
• level:intermediate — 35 pts
• level:advanced — 55 pts
• level:critical — 80 pts

Quality (optional):

• quality:clean — ×1.2 multiplier
• quality:exceptional — ×1.5 multiplier

Validation (required to score):

• gssoc:approved — counts for points
• gssoc:invalid / gssoc:spam / gssoc:ai-slop — does not score

Type labels (type:*) are auto-detected from files and title. Review and adjust if needed.
Points formula: (difficulty × quality_multiplier) + type_bonus