feat: Add acceptSolution and deactivateTask external functions with Natspec documentation

src/academic-learning/TaskBounty.sol

@@ -105,7 +105,10 @@ contract TaskBounty {
      * @param _taskId ID of the task to submit solution for
      * @param _solution The proposed solution
      */
-    function submitSolution(uint256 _taskId, string calldata _solution)
+    function submitSolution(
+        uint256 _taskId,
+        string calldata _solution
+    )
         external
         taskExists(_taskId)
         taskActive(_taskId)
@@ -128,4 +131,54 @@ contract TaskBounty {
 
         emit SolutionSubmitted(_taskId, submissionId, msg.sender, _solution);
     }
+
+    /**
+     * @dev Accept a solution and award the bounty
+     * @param _submissionId ID of the submission to accept
+     */
+    function acceptSolution(uint256 _submissionId) external submissionExists(_submissionId) {
+        Submission storage submission = submissions[_submissionId];
+        uint256 taskId = submission.taskId;
+        Task storage task = tasks[taskId];
+
+        require(msg.sender == task.creator, "Only task creator can accept solutions");
+        require(task.isActive, "Task is not active");
+        require(!task.isCompleted, "Task is already completed");
+        require(!submission.isAccepted, "Submission already accepted");
+
+        // Update task
+        task.isCompleted = true;
+        task.solver = submission.submitter;
+        task.solution = submission.solution;
+        task.solvedAt = block.timestamp;
+
+        // Update submission
+        submission.isAccepted = true;
+
+        // Transfer reward to solver
+        if (task.reward > 0) {
+            payable(submission.submitter).transfer(task.reward);
+        }
+
+        emit BountyClaimed(taskId, _submissionId, submission.submitter, task.reward);
+    }
+
+    /**
+     * @dev Deactivate a task (only creator can do this)
+     * @param _taskId ID of the task to deactivate
+     */
+    function deactivateTask(uint256 _taskId) external taskExists(_taskId) onlyTaskCreator(_taskId) {
+        Task storage task = tasks[_taskId];
+        require(task.isActive, "Task is already inactive");
+        require(!task.isCompleted, "Cannot deactivate completed task");
+
+        task.isActive = false;
+
+        // Refund reward to creator
+        if (task.reward > 0) {
+            payable(task.creator).transfer(task.reward);
+        }
+
+        emit TaskDeactivated(_taskId, msg.sender);
+    }
 }