refactor(cli): improve plugin filter option validation

[hanna-skryl]

Fixes #565

• Ensure warnings for invalid plugin filter options are logged regardless of the --verbose flag.
• Improve message clarity by handling both singular and plural cases.
• Update unit tests to reflect changes in logging behavior and message wording.

[github-actions]

Code PushUp

🤨 Code PushUp report has both improvements and regressions – compared target commit 17f4120 with source commit 29c39ef.

🕵️ See full comparison in Code PushUp portal 🔍

🏷️ Categories

🏷️ Category	⭐ Previous score	⭐ Current score	🔄 Score change
Performance	🔴 46	🟡 51
Security	🟡 89	🟡 88
Code coverage	🟡 90	🟡 90
Custom checks	🟡 67	🟡 67	–
Updates	🟡 78	🟡 78	–
Accessibility	🟢 91	🟢 91	–
Best Practices	🟢 100	🟢 100	–
SEO	🟡 61	🟡 61	–
Bug prevention	🟢 100	🟢 100	–
Code style	🟢 99	🟢 99	–

👍 2 groups improved, 👎 1 group regressed, 👍 6 audits improved, 👎 1 audit regressed, 13 audits changed without impacting score

🗃️ Groups

🔌 Plugin	🗃️ Group	⭐ Previous score	⭐ Current score	🔄 Score change
Lighthouse	Performance	🔴 46	🟡 51
JS Packages	NPM audit	🟡 89	🟡 88
Code coverage	Code coverage metrics	🟡 90	🟡 90

17 other groups are unchanged.

🛡️ Audits

🔌 Plugin	🛡️ Audit	📏 Previous value	📏 Current value	🔄 Value change
Lighthouse	Speed Index	🟥 6.7 s	🟨 5.5 s
Lighthouse	First Contentful Paint	🟥 3.3 s	🟨 2.9 s
Lighthouse	First Meaningful Paint	🟨 3.3 s	🟨 2.9 s
Lighthouse	Largest Contentful Paint	🟨 3.9 s	🟨 3.6 s
JS Packages	Vulnerabilities for NPM dev dependencies.	🟥 11 vulnerabilities (3 high, 8 moderate)	🟥 12 vulnerabilities (3 high, 9 moderate)
Lighthouse	Time to Interactive	🟥 16.9 s	🟥 15.5 s
Code coverage	Branch coverage	🟨 85 %	🟨 85 %
Lighthouse	Minimizes main-thread work	🟥 23.1 s	🟥 17.4 s
Lighthouse	Total Blocking Time	🟥 8,680 ms	🟥 5,530 ms
Lighthouse	Avoids enormous network payloads	🟩 Total size was 1,840 KiB	🟩 Total size was 1,838 KiB
Lighthouse	JavaScript execution time	🟥 10.7 s	🟥 8.4 s
Lighthouse	Metrics	🟩 100%	🟩 100%
Lighthouse	Max Potential First Input Delay	🟥 3,490 ms	🟥 2,720 ms
Lighthouse	Eliminate render-blocking resources	🟥 Potential savings of 1,530 ms	🟥 Potential savings of 870 ms
Lighthouse	Uses efficient cache policy on static assets	🟨 27 resources found	🟨 27 resources found
Lighthouse	Reduce unused CSS	🟥 Potential savings of 106 KiB	🟥 Potential savings of 106 KiB
Lighthouse	Server Backend Latencies	🟩 220 ms	🟩 170 ms
Lighthouse	Initial server response time was short	🟩 Root document took 380 ms	🟩 Root document took 340 ms
Lighthouse	Network Round Trip Times	🟩 20 ms	🟩 50 ms
Code coverage	Line coverage	🟩 91.9 %	🟩 91.9 %

493 other audits are unchanged.