Improve Test Coverage for `challengeCtrl.js` (Current: 61.24%)

**Description:**

The file `EvalAI/frontend/src/js/controllers/challengeCtrl.js` currently has **61.24%** test coverage (as per Codecov). To improve this, comprehensive unit tests need to be added targeting untested and partially covered functionality — especially around API-driven logic, asynchronous behaviors, and UI state transitions.

This issue proposes enhancing coverage through **mocking, controlled inputs**, and **Jasmine’s `spyOn`** to simulate and verify the behavior of key functions.

---

### ✅ Key Areas to Cover

#### 1. **API Interactions**

Functions: `manageWorker`, `sendApprovalRequest`, `getTeamName`

* [ ] Mock `utilities.sendRequest`
* [ ] Validate:

* Proper API parameters
* Success callback handling
* Error handling with appropriate alerts or state fallback

#### 2. **UI Controls & Toggles**

Functions: `toggleParticipation`, `toggleLeaderboard`, `toggleShowLeaderboardByLatest`

* [ ] Mock:

* `$mdDialog`
* `$interval`
* `$rootScope.notify`
* [ ] Validate correct toggling of UI states and user feedback messaging

#### 3. **Leaderboard & Time-based Logic**

Function: `getAllEntriesOnPublicLeaderboard`

* [ ] Mock timestamps using `moment.js`
* [ ] Validate:

* Proper leaderboard grouping by time periods (e.g., "Today", "Yesterday")
* Accurate date formatting and category rendering

#### 4. **Form & Submission Metadata Handling**

Functions: `loadPhaseAttributes`, `isCurrentSubmissionMetaAttributeValid`, `toggleSelection`

* [ ] Simulate realistic phase and metadata input
* [ ] Test for correct validation logic and state updates

---

### 📈 Goal

Increase test coverage for `challengeCtrl.js` to **90%+**, ensuring:

* All asynchronous behaviors are properly tested
* UI state and transitions are fully verified
* External dependencies (e.g., `$mdDialog`, `moment`, `utilities.sendRequest`) are reliably mocked
* Future refactors or regressions are caught early

---