Add trailing whitespace checking and fixing infrastructure

- Add check-trailing-whitespace Makefile target to detect trailing
  whitespaces in source files
- Add fix-trailing-whitespace Makefile target to automatically remove
  trailing whitespaces
- Create CI workflow to check for trailing whitespaces on all pushes
- Update CLAUDE.md with trailing whitespace removal requirements
- Wrap Makefile target commands to 80 characters for better readability

All file types covered: .rs, .toml, .md, .yaml, .yml, .json, .ts, .tsx,
.js, .jsx with appropriate directory exclusions for build artifacts and
dependencies.

Author: dannywillems

.github/workflows/whitespace-check.yaml

@@ -0,0 +1,17 @@
+name: Trailing Whitespace Check
+
+on:
+  push:
+    branches: [ main, develop ]
+  pull_request:
+    branches: [ main, develop ]
+
+jobs:
+  check-whitespace:
+    runs-on: ubuntu-22.04
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Check for trailing whitespaces
+        run: make check-trailing-whitespace

CLAUDE.md

@@ -130,6 +130,7 @@ Each component directory contains a `summary.md` file documenting:
 OpenMina includes a comprehensive documentation website built with Docusaurus:
 
 ### Quick Access
+
 ```bash
 # Start local documentation server
 make docs-serve
@@ -144,16 +145,22 @@ make help | grep docs
 The website is available at http://localhost:3000 when running locally.
 
 ### Structure
-- **Node Runners** (`website/docs/node-runners/`) - Installation and operation guides
-- **Developers** (`website/docs/developers/`) - Architecture and contribution guides
-- **Researchers** (`website/docs/researchers/`) - Protocol and cryptography documentation
+
+- **Node Runners** (`website/docs/node-runners/`) - Installation and operation
+  guides
+- **Developers** (`website/docs/developers/`) - Architecture and contribution
+  guides
+- **Researchers** (`website/docs/researchers/`) - Protocol and cryptography
+  documentation
 
 ### Adding Documentation
+
 1. Create markdown files in the appropriate `website/docs/` subdirectory
 2. Add frontmatter with title, description, and sidebar position
 3. Update `website/sidebars.ts` if needed for navigation
 
-The website supports versioning and will be automatically deployed when commits are made to `develop` or when tags are created.
+The website supports versioning and will be automatically deployed when commits
+are made to `develop` or when tags are created.
 
 ## Additional Resources
 
@@ -203,7 +210,16 @@ referencing Claude.
 
 1. Make your code changes
 2. Run the appropriate formatting command based on file types modified
-3. Verify formatting with check commands if needed
-4. **Verify commit message does not include Claude as co-author**
-5. **Verify commit message contains no emojis and follows 80-character wrap**
-6. Proceed with testing or committing changes
+3. **ALWAYS run `make fix-trailing-whitespace` before committing or ending any task**
+4. Verify formatting with check commands if needed
+5. **Verify commit message does not include Claude as co-author**
+6. **Verify commit message contains no emojis and follows 80-character wrap**
+7. Proceed with testing or committing changes
+
+### Critical Pre-Commit Requirements
+
+- **MANDATORY**: Run `make fix-trailing-whitespace` before every commit
+- **MANDATORY**: Run `make check-trailing-whitespace` to verify no trailing
+  whitespaces remain
+- This applies to ALL file modifications, regardless of file type
+- Trailing whitespaces are strictly prohibited in the codebase

Makefile

@@ -89,6 +89,48 @@ check-md: ## Check if markdown files are properly formatted
 	npx prettier --check "**/*.md"
 	@echo "Markdown format check completed."
 
+.PHONY: fix-trailing-whitespace
+fix-trailing-whitespace: ## Remove trailing whitespaces from all files
+	@echo "Removing trailing whitespaces from all files..."
+	@find . -type f \( \
+		-name "*.rs" -o -name "*.toml" -o -name "*.md" -o -name "*.yaml" \
+		-o -name "*.yml" -o -name "*.json" -o -name "*.ts" -o -name "*.tsx" \
+		-o -name "*.js" -o -name "*.jsx" -o -name "*.sh" \) \
+		-not -path "./target/*" \
+		-not -path "./node_modules/*" \
+		-not -path "./website/node_modules/*" \
+		-not -path "./website/build/*" \
+		-not -path "./website/static/api-docs/*" \
+		-not -path "./website/.docusaurus/*" \
+		-not -path "./.git/*" \
+		-exec sed -i 's/[[:space:]]*$$//' {} + && \
+		echo "Trailing whitespaces removed."
+
+.PHONY: check-trailing-whitespace
+check-trailing-whitespace: ## Check for trailing whitespaces in source files
+	@echo "Checking for trailing whitespaces..."
+	@files_with_trailing_ws=$$(find . -type f \( \
+		-name "*.rs" -o -name "*.toml" -o -name "*.md" -o -name "*.yaml" \
+		-o -name "*.yml" -o -name "*.json" -o -name "*.ts" -o -name "*.tsx" \
+		-o -name "*.js" -o -name "*.jsx" -o -name "*.sh" \) \
+		-not -path "./target/*" \
+		-not -path "./node_modules/*" \
+		-not -path "./website/node_modules/*" \
+		-not -path "./website/build/*" \
+		-not -path "./website/static/api-docs/*" \
+		-not -path "./website/.docusaurus/*" \
+		-not -path "./.git/*" \
+		-exec grep -l '[[:space:]]$$' {} + 2>/dev/null || true); \
+	if [ -n "$$files_with_trailing_ws" ]; then \
+		echo "❌ Files with trailing whitespaces found:"; \
+		echo "$$files_with_trailing_ws" | sed 's/^/  /'; \
+		echo ""; \
+		echo "Run 'make fix-trailing-whitespace' to fix automatically."; \
+		exit 1; \
+	else \
+		echo "✅ No trailing whitespaces found."; \
+	fi
+
 .PHONY: clean
 clean: ## Clean build artifacts
 	cargo clean