test(plugins): add duplicate metadata validation

[HitanshiThakar]

Description

Added a metadata integrity test to detect duplicate plugin IDs and duplicate human-facing plugin names across all plugin metadata files.

The test scans all metadata.json files in the plugins directory and provides clear failure messages listing duplicate entries when found.

Also fixed an existing duplicate plugin display name and refreshed the plugin checksum after updating metadata.

Related Issues

Closes #116

Type of Change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update

How Has This Been Tested?

Ran the backend plugin integrity test locally:

python -m pytest testing/backend/unit/test_plugin_integrity.py -v

Test result:

3 tests passed successfully

Checklist

• My code follows the code style of this project.
• I have performed a self-review of my own code.
• I have commented my code, particularly in hard-to-understand areas.
• I have made corresponding changes to the documentation.
• My changes generate no new warnings.

[ai-slop-guardian]

🛡️ AI Slop Guardian Report

Signal	Value
Overall AI probability	30% 🟢
Perplexity	90%
Burstiness	20%
Pattern	0%
Embedding	50%
DNA	0%
GhostAuthor	0%
SemanticCoherence	60%
Contributor trust	0/100

Verdict: Content shows 30% AI probability based on perplexity, style patterns, and deviation from repo baseline.

Detection details

Perplexity Signals:

• Perplexity score: 16.1 (AI text typically < 30)
• Text is statistically 83.9% more predictable than average human writing

Burstiness Signals:

• Burstiness index: 146.72 (AI typically < 1.5, Human > 4.0)

Pattern Signals:

Embedding Signals:

• No style index exists for this repository yet. Using neutral score.

DNA Signals:

• Unique code signature (Max global similarity: 0.72)

GhostAuthor Signals:

• Insufficient history for ghost author detection (need >= 3 PRs).

SemanticCoherence Signals:

• Low semantic coherence detected (0.39)

Override with /guardian approve · Whitelist with /guardian trust @username

[HitanshiThakar]

1 failing check related to SecuScan CI seems unrelated to the plugin metadata changes in this PR.
The added tests are passing locally.

[utksh1]

Thanks! Since main now normalizes parser line endings for checksum computation (see recent merges), the updated checksum here likely needs a refresh.

Please:

• Rebase on latest main
• Re-run python scripts/refresh_plugin_checksum.py --plugin waf_detector
• Update checksum accordingly and ensure CI passes

The uniqueness test looks good once checksum is correct.

[HitanshiThakar]

Done, All checks have passed.