…2580)

## Summary

- Reverts #2561 (squash commit 769d120), which was merged after #2568
already landed on master
- #2568 +
[shakacode/shakapacker#963](shakacode/shakapacker#963)
fix the root cause of #2438 — #2561's YAML-parsing fallback is redundant
- CHANGELOG entry updated to reference #2568 only

## What's removed

All of #2561's additions on top of #2568:
- `extract_precompile_hook_from_yaml` /
`extract_precompile_hook_from_shakapacker_config` split
- `extract_script_from_command` interpreter-prefix stripping
- `extract_hash_for_environment` / `current_shakapacker_environment`
helpers
- `SHAKAPACKER_CONFIG_PATH` constant, `require "erb"`, `require "yaml"`
- `rubocop:disable Metrics/ModuleLength`
- `GENERATE_PACKS_PATTERN` expansion for `generate_packs_if_needed`
- 72 lines of #2561-specific specs

## What remains (from #2568 + shakapacker#963)

- `project_root` helper (Rails.root → BUNDLE_GEMFILE → Dir.pwd fallback)
- `resolve_hook_script_path` using `project_root`
- `require "pathname"`
- 3 project_root specs
- Shakapacker `Env#current` guard (separate repo, already merged)

## Why

#2568 was designed to supersede #2561 — its PR description says so
explicitly. Both were merged, resulting in unnecessary complexity (YAML
config re-parsing, ERB evaluation, environment fallback chain) that
duplicates what Shakapacker already handles after #963.

## Test plan

- `bundle exec rspec
react_on_rails/spec/react_on_rails/packer_utils_spec.rb`
- `bundle exec rubocop react_on_rails/lib/react_on_rails/packer_utils.rb
react_on_rails/spec/react_on_rails/packer_utils_spec.rb`

🤖 Generated with [Claude Code](https://claude.com/claude-code)

<!-- This is an auto-generated comment: release notes by coderabbit.ai
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## Summary by CodeRabbit

* **Bug Fixes**
* Improved bin/dev startup reliability with enhanced hook script path
resolution during early startup when Rails.root is unavailable.
  * Removed YAML configuration dependency, streamlining hook detection.
* Added validation checks for hook script existence to prevent runtime
errors.
  * Simplified hook script pattern matching for better clarity.

<!-- end of auto-generated comment: release notes by coderabbit.ai -->