sec: Revoke leaked Google API key in Git history and ignore report/ directory in .gitignore

[CodeMaverick-143]

Problem Description

1. API Key in Commit History:
   Commit 5fdbd62 deleted .env from the working tree. However, commits acd7dc2 and c4560a1 contain a committed Google API Key (AIzaSyDogEE6z042tkYJGw7lcVuvLkjmMMLiybU) in Git history. Anyone cloning the repository can extract this key.
2. Missing .gitignore Entries:
   The default output folder report/ (and reports/) is not listed in .gitignore. Running the tool results in generated reports being tracked as untracked files in Git.

Proposed Solution

1. Ensure the leaked API key has been revoked in Google AI Studio / GCP Console.
2. Scrub the Git history using git-filter-repo or BFG Repo-Cleaner if desired.
3. Add report/ and reports/ to .gitignore.