chore(ai-slop): drop the one-release .claude/ai-slop.json team read #13471

Refs #9737

Outcome

/ai-slop:audit reads its team and personal layers only from <home>/ai-slop.yaml and <home>/ai-slop.local.yaml. The repo-relative .claude/ai-slop.json and .claude/ai-slop.local.json fallbacks are gone. They were deprecated in ai-slop 0.15.0 (plugins/ai-slop/CHANGELOG.md:120-131), and 0.16.9 has shipped since. The em-dash purge gate, which copies this repository's detector config and reads it through that fallback, moves to the YAML, so the CI gate's verdict does not change. The user-global $HOME/.claude/ai-slop.json layer stays (detect.sh:220, ADR 0075).

Change

• plugins/ai-slop/skills/audit/scripts/detect.sh:233: drop the .claude/$_name.json fallback, and update the comment at :225-226. Keep USER_CFG (:220) and the jq path for the JSON user layer.
• scripts/check-purged-em-dashes.sh:
  • Today it defaults to .claude/ai-slop.json (:115), exits 2 when that file is unreadable (:137), and writes its throwaway layer to $TMP/root/.claude/ai-slop.json (:337), which detect.sh will no longer read.
  • Make it read docs/conventions/ai-slop.yaml and write its throwaway layer as $TMP/root/docs/conventions/ai-slop.yaml. Override the same keys: replace disabled_rules with every slug except rule-em-dash, strip em_dash_allowed_paths and rule_allowed_paths["rule-em-dash"], and keep excluded_paths and thresholds. jq cannot read YAML, so state the mechanism. One option keeps the copy-not-synthesize property: copy the tracked YAML unchanged to $TMP/root/docs/conventions/ai-slop.yaml and write the overrides as $TMP/root/docs/conventions/ai-slop.local.yaml, after confirming in lib/cascade-read.sh that a later layer's empty list or slug entry replaces an earlier one and that yaml-subset accepts []. Keep the jq prerequisite (:133-136), or change scripts/check-script-contract.test.sh:109 to match.
  • Update its header comment (:45), scripts/check-purged-em-dashes.test.sh:62,77,128-130,345,365,375,386 and scripts/em-dash-purged-paths.txt:46,54.
• Fixtures that configure a temp repo through .claude/ai-slop.json (detect.test.sh, cross-check.test.sh) move to docs/conventions/ai-slop.yaml. A fixture may keep writing the old file only to assert that the file is not read. A case that tests the JSON parser itself (for example detect.test.sh:583, a truncated JSON) moves to the user-global $HOME/.claude/ai-slop.json layer, which jq still reads.
• Docs that describe the fallback:
  • plugins/ai-slop/schemas/ai-slop.schema.json:5 description.
  • plugins/ai-slop/README.md:62-64.
  • The fallback clause at plugins/ai-slop/skills/setup/SKILL.md:28-29. Keep setup's offer to carry an old JSON file into the YAML: the 2026-11-02 decision on chore: drop the one-release .claude config reads and this repository's old config files #9737 keeps setup lines that report or move a retired file. Setup's eval cases do not change.
  • docs/contracts/config-cascade/README.md:658,781.
  • The docs/conventions/ai-slop.yaml:2-5 header: drop the sentence that names the legacy .claude/ai-slop.json and the 'made in both files' sentence.
• Leave .claude/ai-slop.json in place. The lane mounts .claude/ read-only. After this merges, the host slice deletes it.
• Add an ai-slop changelog fragment.

Done when

• git grep -nP '(?<!~/)(?<!HOME/)(?<!\}/)\.claude/(ai-slop(\.local)?\.json|\$_name\.json)' -- plugins/ai-slop scripts docs/conventions/ai-slop.yaml docs/contracts ':!*CHANGELOG*' ':!*.test.sh' prints nothing (on origin/main it prints 11 lines in 6 files).
• git grep -n 'beside them is absent' -- plugins/ai-slop ':!*CHANGELOG*' prints nothing.
• git grep -n 'USER_CFG="${HOME:-/nonexistent}/.claude/ai-slop.json"' -- plugins/ai-slop/skills/audit/scripts/detect.sh prints one line (the user layer stays).
• git diff --name-only origin/main...HEAD -- .claude plugins/ai-slop/skills/setup/evals plugins/ai-slop/evals prints nothing.
• grep -n '^## \[0.16.0\]' plugins/ai-slop/CHANGELOG.md prints one line (a release after the 0.15.0 YAML reader).
• bash scripts/run-test-file.sh plugins/ai-slop/skills/audit/scripts/detect.test.sh exits 0.
• bash scripts/run-test-file.sh plugins/ai-slop/skills/audit/scripts/cross-check.test.sh exits 0.
• bash scripts/run-test-file.sh scripts/check-purged-em-dashes.test.sh exits 0.
• bash scripts/run-test-file.sh scripts/check-script-contract.test.sh exits 0.
• bash scripts/check-purged-em-dashes.sh exits 0.
• scripts/check-changelog-fragments.sh --check-required origin/main exits 0.