Add missing policies and required files

- Never use git add -A; always stage files by name
- Makefile must provide make hooks target for pre-commit setup
- All repos should have .editorconfig
- JS required files: yarn.lock, .prettierrc, .prettierignore
- Python required files: pyproject.toml

REPO_POLICIES.md

@@ -22,7 +22,8 @@
   exception: set four-space indents for everything except Go.
 
 - Pre-commit hook: `make check` if local testing is possible, otherwise
-  `make lint && make fmt-check`.
+  `make lint && make fmt-check`. The Makefile should provide a
+  `make hooks` target to install the pre-commit hook.
 
 - `make test` must complete in under 20 seconds. Add a 30-second timeout
   in the Makefile.
@@ -34,6 +35,9 @@
 
 - `main` must always pass `make check`, no exceptions.
 
+- Never use `git add -A` or `git add .`. Always stage files explicitly
+  by name.
+
 - Make all changes on a feature branch. You can do whatever you want on
   a feature branch.
 
@@ -79,9 +83,13 @@
 - Pre-1.0.0: modify existing migrations (no installed base assumed).
   Post-1.0.0: add new migration files.
 
+- All repos should have an `.editorconfig` enforcing the project's
+  indentation settings.
+
 - New repos must contain at minimum:
-    - `README.md`, `.git`, `.gitignore`
+    - `README.md`, `.git`, `.gitignore`, `.editorconfig`
     - `REPO_POLICIES.md` (copy from the `prompts` repo)
     - `Dockerfile`, `.dockerignore`
     - Go: `go.mod`, `go.sum`, `.golangci.yml`
-    - JS: `package.json`
+    - JS: `package.json`, `yarn.lock`, `.prettierrc`, `.prettierignore`
+    - Python: `pyproject.toml`