#511: Correct sign in Fbe.sec so elapsed seconds format as past

[VasilevNStas]

Description

Fbe.sec used (Time.now + s).ago, which for a positive s formatted a future time as "from now". The method's purpose is to format elapsed seconds (past time), so the sign was wrong.

Fix

Changed line 29 from (Time.now + s).ago to (Time.now - s).ago. Updated YARD docstring to match the actual tago gem output format (short form: "2h" instead of "2 hours ago").

Closes #511

Tests

• test_elapsed_past — verifies that Fbe.sec returns "2h" for a fact with seconds = 7200 (would return "1h59m" with the buggy code)

Verification

• bundle exec rubocop — 0 offenses
• bundle exec rake test — 0 failures

[kreinba]

Sign flip from (Time.now + s).ago to (Time.now - s).ago matches the elapsed-time contract that the method name and YARD example promise, and resolves #511. New test test_elapsed_past pins the 7200-second case to '2h' using Time.stub from minitest/mock (already required in test/test__helper.rb), which is a strict guard the prior start_with?('5m') assertion was missing. Docstring is realigned to the short tago form. CI is green on every check.

[0crat]

@kreinba Great work on the review! 🎉 You've earned +6 points (base +18, -8 for missing comments, -4 for low code coverage with 18 hits). Your total score is now +1538 - keep up the momentum and check your Zerocracy account for updates!

[yegor256]

@VasilevNStas merge conflict here

[yegor256]

Please fix the merge conflicts so this pull request can be merged.

[VasilevNStas]

@yegor256 plz re-review