🗄 [chore] prevent bash only feature in script

Author: tomy0000000

.claude/hookify.warn-bash-only-features.local.md

@@ -0,0 +1,26 @@
+---
+name: warn-bash-only-features
+enabled: true
+event: file
+conditions:
+  - field: file_path
+    operator: regex_match
+    pattern: \.sh$
+---
+
+⚠️ **Bash-only feature detected in a `*.sh` script**
+
+`*.sh` scripts in this repo should avoid bash-only features so they stay portable to POSIX `sh`. The pattern above caught **`BASH_SOURCE`**, but it's only one example. Other bash-only constructs to avoid:
+
+- `BASH_*` builtins (`BASH_SOURCE`, `BASH_VERSION`, `BASH_REMATCH`, …)
+- `[[ ... ]]` conditionals (use `[ ... ]`)
+- `<<<` here-strings
+- `<(...)` process substitution
+- `(( ... ))` arithmetic commands
+- bash arrays (`arr=(...)`, `${arr[@]}`)
+- `${var,,}` / `${var^^}` case modification
+- `local` (POSIX `sh` has no equivalent)
+
+**Specific to `BASH_SOURCE` in `pkg/**/\*.sh`:** those scripts run from the repo root via `make`/ the`run`helper, so paths should be hardcoded as`pkg/{name}/...`(see auto-memory`feedback_script_paths.md`). Don't derive them from `BASH_SOURCE`.
+
+If a script genuinely needs bash, change its shebang/extension and note why.