CLAUDE.md git:20261014.4b1ff47A

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@AGENTS.md

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## Hooks

`hooks/hooks.json` defines one PostToolUse hook and one PreToolUse hook.

- `Edit|MultiEdit|Write` matcher → `validate_layers.sh`. The matcher is a filter, not a guarantee, so the hook reads `tool_name` from the payload and exits 0 unless it is `Edit`, `MultiEdit`, or `Write`. When the edited file is a `pubspec.yaml` inside an FFCA-shaped repo, meaning a `features/` folder exists above it, the hook runs `dart run scripts/validate_layers.dart --file <pubspec>`. The validator checks the edited package and its direct dependents. Exit 2 means a layer violation. The hook prints the rule and the fix to stderr and exits 2, which blocks Claude until the dependency is fixed.
- Any other file, or a repo with no `features/` folder, exits 0 silently.
- The hook skips with exit 0 when `jq` or `dart` is missing from `PATH`. The `dart` check runs only for FFCA pubspec edits. A validator failure other than exit 2 is reported to stderr but never blocks.

- `mcp__.*very-good-cli__.*` matcher → `check_vgv_cli.sh`. For a Very Good CLI MCP tool, it returns `allow` when `very_good --version` is 1.3.0 or newer and `deny` with an install or upgrade message when the CLI is missing or older. It stands aside with exit 0 for any other tool, when the version cannot be read, or when `jq` is missing. `allowed-tools` grants only last for the invoking turn, so this hook is what keeps the tools approved afterwards.

`hooks/check_vgv_cli_test.sh` covers the PreToolUse hook against a stubbed `very_good` and runs in CI under the **Hook Tests** job.

`scripts/test/validate_layers_test.dart` covers the validator and runs in CI under the **Layer Validator** job. Add a fixture and a case there when changing a rule.

`hooks/validate_layers_test.sh` covers the PostToolUse hook against the same fixtures and runs in CI under the **Hook Tests** job.