docs: fix typos in S3 comments and correct SFTP Getwd logging

[Vegapunk-debug]

Description:

• Noticed a few stale "FTP" references in the S3 package (likely leftovers from a past copy-paste) and a small logging bug in the SFTP provider.

  • Fixed "FTP" typos in s3/fs.go comments and corrected a minor grammar slip in the Connect method.
  • Corrected the Getwd method in sftp/fs.go, which was incorrectly logging the operation as "STAT" instead of "GETWD".
  • Clarified the SFTP Connect comments to specify it's an SFTP server.

• Mention the issue number(s) this PR addresses (if applicable).
  N/A

• Highlight the motivation behind the changes and the expected benefits.
  Bring the documentation in line with the actual implementations and fix a minor observability bug in the SFTP logs developers see the correct operation name.

Additional Information:

• Mention any relevant dependencies or external libraries used.
  None.

• Include screenshots or code snippets (if necessary) to clarify the changes.
  These are strictly non-functional comment and string fixes, so they are zero-risk to the core logic.

Checklist:

• I have formatted my code using goimport and golangci-lint.
• All new code is covered by unit tests. (Note: No new logic was added, just comment/log string fixes)
• This PR does not decrease the overall code coverage.
• I have reviewed the code comments and documentation for clarity.

Thank you!

[Vegapunk-debug]

@aryanmehrotra, please review my PR.