Tests: cover issue snapshots and add 8.5/next set coverage

[ohmyfelix]

Summary

• add a new IssueTest data-provider suite so snapshot fixtures in tests/Issue/* are executed by PHPUnit
• add tests/Sets/8.5 and tests/Sets/next with ruleset wrappers, fixtures, and generated snapshots to keep versioned set coverage aligned with available rulesets
• harden SniffTest and RulesetTest process handling by asserting successful phpcs execution and strict JSON decoding while keeping non-zero lint findings from failing process exit
• add docs/CI follow-ups: generate ruleset-8.5 docs, update ruleset examples, guard snapshot drift in workflow, and prevent filename-key collisions in Codesniffer::normalize()
• add P2 automation: ruleset/set parity validation and generated ruleset diff report artifact in CI
• add P3 regression tests for Codesniffer::normalize() duplicate-basename behavior

TODO

• Fork and clone repository, create chore/ruleset-analysis branch
• Run baseline test suite (phpunit, paratest) and verify green state
• Add PHPUnit coverage for issue snapshots via tests/Cases/IssueTest.php
• Add missing ruleset set coverage for 8.5 and next under tests/Sets
• Harden PHPCS process handling and JSON decoding in snapshot tests
• Update docs generation to include ruleset-8.5 in Makefile and .docs/rulesets
• Remove basename collision risk in tests/Toolkit/Codesniffer.php by using deterministic unique keys
• Add CI guard for snapshot drift (php bin/snapshots must be clean)
• Add parity check between ruleset-*.xml and tests/Sets/*
• Add ruleset diff report generation and upload it as CI artifact
• Add direct unit tests for Codesniffer::normalize() key behavior

Testing

• vendor/bin/phpunit
• vendor/bin/paratest
• php bin/snapshots
• bash .dev/check-ruleset-sets-parity.sh
• bash .dev/ruleset-diff-report.sh

[ohmyfelix]

Added a machine-readable sniff coverage matrix and wired it to CI artifacts.

What is now generated in CI (Snapshots job):

• .reports/sniff-coverage-matrix.csv
• .reports/sniff-coverage-summary.md

How it works:

• reads enabled sniffs from vendor/bin/phpcs --standard=ruleset.xml -e
• maps sniff refs from tests/Sniffs/**/*.ruleset.xml
• outputs per-enabled-sniff fields:
  • enabled_sniff
  • has_tests
  • fixture_count
  • has_good
  • has_bad
  • custom_count
  • directories

Latest local run summary:

• Total enabled sniffs: 185
• With dedicated tests: 185
• Missing dedicated tests: 0
• Weak examples: 2
  • Generic.Files.ByteOrderMark
  • Generic.Files.LineEndings

Once checks finish, download artifact: sniff-coverage-matrix.