feat(python): add Two Sum solution (LeetCode #1)

.github/PULL_REQUEST_TEMPLATE.md

@@ -0,0 +1,24 @@
+<!-- Pull Request template for codedecks-in/LeetCode-Solutions -->
+
+<!-- Please fill out the checklist below before opening the PR. This helps the maintainers review faster. -->
+
+### Summary
+
+Provide a short description of the change in this pull request.
+
+### Checklist
+
+- [ ] PR title follows the format: `<type>: <short description>` (e.g. `fix: correct typo in solution`)
+- [ ] PR description explains what and why (include references to issues if applicable)
+- [ ] All new code is commented and follows repository style
+- [ ] Relevant tests have been added or updated
+- [ ] I have run the test suite locally and all tests pass
+- [ ] The change is limited to a single problem or logical change
+
+### Related Issue
+
+If this PR addresses an existing issue, link it here: #
+
+### Notes for Reviewers
+
+Any additional information for reviewers or special steps to test.

CHANGELOG.md

@@ -0,0 +1,8 @@
+# Changelog
+
+This repository follows a simple changelog to keep track of notable changes.
+
+## Unreleased
+
+- test: add placeholder PR validation script and PR template for CI workflow testing
+

Python/Two_Sum/solution.py

@@ -0,0 +1,19 @@
+# LeetCode Problem: Two Sum
+# URL: https://leetcode.com/problems/two-sum/
+# Language: Python 3
+
+from typing import List
+
+class Solution:
+    def twoSum(self, nums: List[int], target: int) -> List[int]:
+        seen = {}
+        for i, v in enumerate(nums):
+            need = target - v
+            if need in seen:
+                return [seen[need], i]
+            seen[v] = i
+
+# Example quick test runner (optional)
+if __name__ == "__main__":
+    s = Solution()
+    print(s.twoSum([2,7,11,15], 9))  # expected [0, 1]

scripts/validate_pr.py

@@ -0,0 +1,19 @@
+#!/usr/bin/env python3
+import os
+import sys
+
+# Minimal non-failing PR validation placeholder
+# Prints environment variables provided by the workflow so we can inspect them in the job logs.
+
+def main():
+    print("validate_pr: placeholder — environment:")
+    print("PR_TITLE =", os.getenv("PR_TITLE"))
+    print("PR_BODY  =", os.getenv("PR_BODY"))
+    print("BASE_SHA =", os.getenv("BASE_SHA"))
+    print("HEAD_SHA =", os.getenv("HEAD_SHA"))
+    # Add a simple hint to be visible in logs
+    print("validate_pr: placeholder script completed successfully.")
+    return 0
+
+if __name__ == '__main__':
+    sys.exit(main())