Add deterministic configure script for scaffold placeholders

[retlehs]

Summary

• add configure.php for deterministic, interactive placeholder replacement after package scaffolding
• update template files and rename class/config/view files using explicit mappings
• mutate composer.json structurally (JSON parse/write) and keep 2-space formatting
• add --dry-run, --no-interaction, and --yes flags
• remove scaffold-only maintenance artifacts from generated packages (test:configure script, smoke workflow, smoke script)
• add smoke test + CI workflow in this repo to validate configure behavior

How to run

Interactive:

php configure.php

Dry run:

php configure.php --dry-run

Non-interactive:

php configure.php --no-interaction --yes \
  --author-name="Your Name" \
  --author-email="you@example.com" \
  --vendor-slug="your-vendor" \
  --vendor-namespace="YourVendor" \
  --package-slug="your-package" \
  --class-name="YourPackage" \
  --package-description="Your package description"

Verification

• composer test:configure
• manual end-to-end run in a temp copy

Closes #5

Docs updates: roots/docs#565