feat(structure): migrate Ralph files to .ralph/ subfolder (#109)

* feat(structure): migrate Ralph files to .ralph/ subfolder

BREAKING CHANGE: Ralph configuration files now live in .ralph/ subfolder

This refactoring moves all Ralph-specific files into a hidden .ralph/
directory while keeping src/ at the project root. This improves
compatibility with existing tooling and keeps the project root clean.

Changes:
- Move PROMPT.md, @fix_plan.md, @AGENT.md to .ralph/
- Move specs/, logs/, docs/generated/, examples/ to .ralph/
- Move state files (.response_analysis, .circuit_breaker_state, etc.) to .ralph/
- Keep src/ at project root (unchanged)
- Add RALPH_DIR=".ralph" configuration variable
- Add ralph-migrate command for existing projects
- Create migrate_to_ralph_folder.sh migration script
- Update all path references in scripts and tests
- Update documentation (README.md, CLAUDE.md)

New project structure:
  project/
  ├── .ralph/           # Ralph configuration
  │   ├── PROMPT.md
  │   ├── @fix_plan.md
  │   ├── @AGENT.md
  │   ├── specs/
  │   ├── logs/
  │   └── docs/generated/
  └── src/              # Source code (unchanged)

Migration: Run `ralph-migrate` in existing projects to upgrade.

All 310 tests pass (100% pass rate).

* chore: add .claude/settings.local.json to .gitignore

* fix: address code review feedback for .ralph/ subfolder structure

Fixes multiple path-related issues identified in code review:

Test fixes:
- Fix create_sample_prompt to use $RALPH_DIR/PROMPT.md in test_session_continuity.bats
- Fix result_file path to use $RALPH_DIR/.json_parse_result in test_json_parsing.bats
- Fix @fix_plan.md and .response_analysis paths in test_cli_modern.bats
- Update templates directory missing test to account for global fallback

Template fix:
- Fix @fix_plan.md reference in templates/PROMPT.md to use .ralph/ prefix

Script fixes:
- Fix PROMPT_FILE comparison in ralph_loop.sh to use $RALPH_DIR/PROMPT.md
- Fix examples migration logic in migrate_to_ralph_folder.sh (remove premature mkdir)
- Move templates directory check AFTER cd in setup.sh (was checking wrong location)
- Add template directory validation with fallback to global templates

All 310 tests pass.

* Update migrate_to_ralph_folder.sh

Co-authored-by: macroscopeapp[bot] <170038800+macroscopeapp[bot]@users.noreply.github.com>

* fix: address code review feedback for .ralph/ subfolder structure

Code Review Fixes:
- Fix test_json_parsing.bats: all result_file and session file paths now use $RALPH_DIR prefix
- Fix ralph_loop.sh help text: paths now show .ralph/.ralph_session, .ralph/.call_count, etc.
- Fix migrate_to_ralph_folder.sh:
  - Proper error handling for date command (separate local declaration)
  - Use cp -a source/. dest/ pattern to preserve dotfiles and attributes
  - Remove 2>/dev/null suppression to surface copy errors
- Update create_files.sh to use .ralph/ structure for embedded scripts
- Update .gitignore with all .ralph/ state file paths
- Add old structure detection in ralph_loop.sh with helpful migration message

Version Update:
- Bump to v0.10.0 (breaking change: structural reorganization)
- Update README.md and CLAUDE.md with new version and release notes
- Add ralph-migrate documentation to Key Commands section

All 310 tests pass.

---------

Co-authored-by: macroscopeapp[bot] <170038800+macroscopeapp[bot]@users.noreply.github.com>

templates/AGENT.md

@@ -94,9 +94,9 @@ Before moving to the next feature, ALL changes must be:
    - Create pull requests for all significant changes
 
 4. **Ralph Integration**:
-   - Update @fix_plan.md with new tasks before starting work
-   - Mark items complete in @fix_plan.md upon completion
-   - Update PROMPT.md if development patterns change
+   - Update .ralph/@fix_plan.md with new tasks before starting work
+   - Mark items complete in .ralph/@fix_plan.md upon completion
+   - Update .ralph/PROMPT.md if development patterns change
    - Test features work within Ralph's autonomous loop
 
 ### Documentation Requirements
@@ -137,10 +137,10 @@ Before marking ANY feature as complete, verify:
 - [ ] Type checking passes (if applicable)
 - [ ] All changes committed with conventional commit messages
 - [ ] All commits pushed to remote repository
-- [ ] @fix_plan.md task marked as complete
+- [ ] .ralph/@fix_plan.md task marked as complete
 - [ ] Implementation documentation updated
 - [ ] Inline code comments updated or added
-- [ ] AGENT.md updated (if new patterns introduced)
+- [ ] .ralph/@AGENT.md updated (if new patterns introduced)
 - [ ] Breaking changes documented
 - [ ] Features tested within Ralph loop (if applicable)
 - [ ] CI/CD pipeline passes
@@ -149,7 +149,7 @@ Before marking ANY feature as complete, verify:
 
 These standards ensure:
 - **Quality**: High test coverage and pass rates prevent regressions
-- **Traceability**: Git commits and @fix_plan.md provide clear history of changes
+- **Traceability**: Git commits and .ralph/@fix_plan.md provide clear history of changes
 - **Maintainability**: Current documentation reduces onboarding time and prevents knowledge loss
 - **Collaboration**: Pushed changes enable team visibility and code review
 - **Reliability**: Consistent quality gates maintain production stability