diff --git a/.github/ISSUE_TEMPLATE/bug_report.md b/.github/ISSUE_TEMPLATE/bug_report.md
new file mode 100644
index 0000000000..57c6cafa40
--- /dev/null
+++ b/.github/ISSUE_TEMPLATE/bug_report.md
@@ -0,0 +1,41 @@
+---
+name: Bug Report
+about: Create a report to help us improve
+title: "[BUG] "
+labels: bug
+assignees: ""
+
+---
+
+## Bug Description
+A clear and concise description of what the bug is.
+
+## Steps to Reproduce
+1. Go to "..."
+2. Click on "..."
+3. Scroll down to "..."
+4. See error
+
+## Expected Behavior
+A clear and concise description of what you expected to happen.
+
+## Actual Behavior
+A clear and concise description of what actually happened.
+
+## Screenshots
+If applicable, add screenshots to help explain your problem.
+
+## Environment
+- OS: [e.g. iOS, Windows, Linux]
+- Browser: [e.g. Chrome, Firefox, Safari]
+- Version: [e.g. 22]
+- Node.js version: [e.g. 18.17.0]
+
+## Additional Context
+Add any other context about the problem here.
+
+## Logs
+```
+Paste relevant logs here
+```
+
diff --git a/.github/ISSUE_TEMPLATE/feature_request.md b/.github/ISSUE_TEMPLATE/feature_request.md
new file mode 100644
index 0000000000..e5f154b52e
--- /dev/null
+++ b/.github/ISSUE_TEMPLATE/feature_request.md
@@ -0,0 +1,35 @@
+---
+name: Feature Request
+about: Suggest an idea for this project
+title: "[FEATURE] "
+labels: enhancement
+assignees: ""
+
+---
+
+## Feature Description
+A clear and concise description of what you want to happen.
+
+## Problem Statement
+Is your feature request related to a problem? Please describe.
+A clear and concise description of what the problem is. Ex. I am always frustrated when [...]
+
+## Proposed Solution
+Describe the solution you would like
+A clear and concise description of what you want to happen.
+
+## Alternatives Considered
+Describe alternatives you have considered
+A clear and concise description of any alternative solutions or features you have considered.
+
+## Benefits
+- Benefit 1
+- Benefit 2
+- Benefit 3
+
+## Implementation Notes
+Any specific technical considerations or implementation details.
+
+## Additional Context
+Add any other context or screenshots about the feature request here.
+
diff --git a/.github/pull_request_template.md b/.github/pull_request_template.md
new file mode 100644
index 0000000000..5b08ca7560
--- /dev/null
+++ b/.github/pull_request_template.md
@@ -0,0 +1,42 @@
+## Description
+Brief description of the changes in this PR.
+
+## Type of Change
+- [ ] 🐛 Bug fix (non-breaking change which fixes an issue)
+- [ ] ✨ New feature (non-breaking change which adds functionality)
+- [ ] 💥 Breaking change (fix or feature that would cause existing functionality to not work as expected)
+- [ ] 📚 Documentation update
+- [ ] 🔧 Refactor (code change that neither fixes a bug nor adds a feature)
+- [ ] ⚡ Performance improvement
+- [ ] 🧪 Test addition or update
+
+## Changes Made
+- Change 1
+- Change 2
+- Change 3
+
+## Testing
+- [ ] Unit tests added/updated
+- [ ] Integration tests added/updated
+- [ ] Visual regression tests passed
+- [ ] Manual testing completed
+
+## Screenshots (if applicable)
+Please add screenshots to help explain your changes.
+
+## Checklist
+- [ ] My code follows the project style guidelines
+- [ ] I have performed a self-review of my own code
+- [ ] I have commented my code, particularly in hard-to-understand areas
+- [ ] I have made corresponding changes to the documentation
+- [ ] My changes generate no new warnings
+- [ ] I have added tests that prove my fix is effective or that my feature works
+- [ ] New and existing unit tests pass locally with my changes
+- [ ] Any dependent changes have been merged and published
+
+## Related Issues
+Closes #(issue_number)
+
+## Additional Notes
+Any additional information that might be helpful for reviewers.
+
diff --git a/.github/workflows/ci-cd.yml b/.github/workflows/ci-cd.yml
new file mode 100644
index 0000000000..8cec04bbb6
--- /dev/null
+++ b/.github/workflows/ci-cd.yml
@@ -0,0 +1,153 @@
+name: CI/CD Pipeline
+
+on:
+  push:
+    branches: [leader, main]
+  pull_request:
+    branches: [leader, main]
+
+jobs:
+  # 1. Fast, parallel validation for linting and unit tests
+  unit_tests:
+    runs-on: ubuntu-latest # 2-core runner is sufficient for fast tests
+    strategy:
+      matrix:
+        node-version: [18.x, 20.x]
+    
+    steps:
+    - name: Checkout Code
+      uses: actions/checkout@v4
+    
+    - name: Setup Node.js ${{ matrix.node-version }}
+      uses: actions/setup-node@v4
+      with:
+        node-version: ${{ matrix.node-version }}
+        cache: "npm"
+        
+    - name: Install Dependencies
+      # The `npm ci` is fast enough if caching is effective.
+      run: npm ci
+    
+    - name: Run Linting and Formatting Checks
+      run: |
+        npm run lint
+        npm run format:check
+    
+    - name: Run Unit Tests
+      run: npm run test:coverage
+      
+    - name: Upload Coverage (runs only once per matrix iteration)
+      uses: codecov/codecov-action@v3
+      with:
+        # Use a flag to differentiate coverage runs in Codecov UI
+        flags: node-${{ matrix.node-version }}-unittests
+        file: ./coverage/lcov.info
+
+  # 2. Sequential, resource-heavy build and E2E/visual tests (runs only once)
+  build_and_e2e:
+    needs: [unit_tests]
+    # For self-hosted or larger runners, specify here:
+    # runs-on: self-hosted-8core 
+    runs-on: ubuntu-latest # Consider upgrading this to ubuntu-latest-8-cores for speed
+    
+    # We only need the latest, validated Node version here.
+    steps:
+    - name: Checkout Code
+      uses: actions/checkout@v4
+
+    - name: Setup Node.js 20.x
+      uses: actions/setup-node@v4
+      with:
+        node-version: "20.x"
+        cache: "npm"
+        
+    - name: Install Dependencies
+      run: npm ci
+
+    - name: 🏗️ Next.js Production Build Cache Restore
+      # This is the most critical step for performance.
+      # Utilize the Next.js cache feature for subsequent runs.
+      uses: actions/cache/restore@v3
+      with:
+        path: |
+          .next/cache
+        key: ${{ runner.os }}-nextjs-${{ hashFiles('**/package-lock.json', '**/*.ts', '**/*.tsx') }}
+        restore-keys: |
+          ${{ runner.os }}-nextjs-
+    
+    - name: Execute Build
+      run: npm run build
+      
+    - name: 💾 Save Next.js Build Cache
+      uses: actions/cache/save@v3
+      with:
+        path: .next/cache
+        key: ${{ runner.os }}-nextjs-${{ hashFiles('**/package-lock.json', '**/*.ts', '**/*.tsx') }}
+
+    - name: 🖼️ Run Visual Regression Tests (Playwright)
+      # This step should only run once after a successful build.
+      # You may want to configure Playwright to cache its browser binaries too.
+      run: npm run test:visual
+      
+    - name: Upload Test Artifacts on Failure
+      uses: actions/upload-artifact@v4
+      if: failure()
+      with:
+        name: test-artifacts
+        path: |
+          tests/playwright/screenshots/
+          tests/playwright/test-results/
+
+    - name: 📦 Upload Build Artifact
+      uses: actions/upload-artifact@v4
+      with:
+        name: production-build-output
+        path: |
+          .next/
+          dist/
+          node_modules/
+          package.json
+          pnpm-lock.yaml
+          next.config.js
+          ecosystem.config.cjs
+
+  # 3. Security remains separate
+  security:
+    runs-on: ubuntu-latest
+    steps:
+    - name: Checkout code
+      uses: actions/checkout@v4
+      
+    - name: Setup Node.js
+      uses: actions/setup-node@v4
+      with:
+        node-version: "20.x"
+        cache: "npm"
+    
+    - name: Install dependencies
+      run: npm ci
+    
+    - name: Run security audit
+      run: npm audit --audit-level=high
+      
+    - name: Run custom security scan
+      run: ./scripts/security-audit.sh || true
+
+  # 4. Deployment now depends on the single build step
+  # deploy:
+  #   needs: [build_and_e2e, security]
+  #   runs-on: ubuntu-latest
+  #   if: github.ref == "refs/heads/leader" && github.event_name == "push"
+    
+  #   steps:
+  #   # NOTE: You no longer need to run `npm ci` and `npm run build` here. 
+  #   # The artifact from `build_and_e2e` should be used.
+    
+  #   - name: ⬇️ Download Build Artifact
+  #     uses: actions/download-artifact@v4
+  #     with:
+  #       name: production-build-output
+  #       path: .
+        
+  #   - name: Deploy Notification
+  #     run: echo "Deployment would happen here, using the downloaded build artifact."
\ No newline at end of file
diff --git a/.github/workflows/pr-quality.yml b/.github/workflows/pr-quality.yml
new file mode 100644
index 0000000000..42571ef436
--- /dev/null
+++ b/.github/workflows/pr-quality.yml
@@ -0,0 +1,47 @@
+name: PR Quality Gate
+
+on:
+  workflow_dispatch:
+
+jobs:
+  pr-quality:
+    runs-on: ubuntu-latest
+    
+    steps:
+    - name: Checkout code
+      uses: actions/checkout@v4
+      with:
+        fetch-depth: 0
+    
+    - name: Setup Node.js
+      uses: actions/setup-node@v4
+      with:
+        node-version: "20.x"
+        cache: "npm"
+    
+    - name: Install dependencies
+      run: npm ci
+    
+    - name: Check PR title format
+      run: |
+        # This check is informational for manual runs.
+        # In a real PR context, you would use github.event.pull_request.title
+        echo "Note: This check is for a manual run. In a PR, it would validate the title."
+
+    - name: Check for large files
+      run: |
+        find . -type f -size +1M -not -path "./node_modules/*" -not -path "./.git/*" | while read file; do
+          echo "::warning::Large file detected: $file ($(du -h "$file" | cut -f1))"
+        done
+    
+    - name: Lint commit messages
+      run: |
+        echo "Note: This check is for a manual run. In a PR, it would lint commit messages."
+        if git rev-parse --verify HEAD~1 >/dev/null 2>&1; then
+          git log --oneline HEAD~1..HEAD | while read line; do
+            if [[ ! "$line" =~ ^[a-f0-9]+\ (feat|fix|docs|style|refactor|test|chore|perf|ci)(\(.+\))?: ]]; then
+              echo "::warning::Commit message should follow conventional commits: $line"
+            fi
+          done
+        fi
+
diff --git a/.github/workflows/security-scan.yml b/.github/workflows/security-scan.yml
new file mode 100644
index 0000000000..c5329c21d8
--- /dev/null
+++ b/.github/workflows/security-scan.yml
@@ -0,0 +1,55 @@
+name: Dependency Security Scan
+
+on:
+  schedule:
+    - cron: "0 6 * * 1" # Every Monday at 6 AM
+  workflow_dispatch: # Allow manual trigger
+
+jobs:
+  security-scan:
+    runs-on: ubuntu-latest
+    
+    steps:
+    - name: Checkout code
+      uses: actions/checkout@v4
+    
+    - name: Setup Node.js
+      uses: actions/setup-node@v4
+      with:
+        node-version: "20.x"
+        cache: "npm"
+    
+    - name: Install dependencies
+      run: npm ci
+    
+    - name: Run comprehensive security audit
+      run: |
+        echo "## Security Audit Report - $(date)" >> $GITHUB_STEP_SUMMARY
+        echo "### NPM Audit" >> $GITHUB_STEP_SUMMARY
+        npm audit --audit-level=low --json > audit.json || true
+        echo "\`\`\`json" >> $GITHUB_STEP_SUMMARY
+        cat audit.json >> $GITHUB_STEP_SUMMARY
+        echo "\`\`\`" >> $GITHUB_STEP_SUMMARY
+    
+    - name: Check for security vulnerabilities
+      run: |
+        VULNERABILITIES=$(npm audit --audit-level=high --json | jq ".metadata.vulnerabilities.total")
+        echo "Found $VULNERABILITIES high+ severity vulnerabilities"
+        if [ "$VULNERABILITIES" -gt 0 ]; then
+          echo "::warning::Found $VULNERABILITIES high+ severity vulnerabilities"
+          npm audit --audit-level=high
+        fi
+    
+    - name: Create issue on security findings
+      if: failure()
+      uses: actions/github-script@v6
+      with:
+        script: |
+          github.rest.issues.create({
+            owner: context.repo.owner,
+            repo: context.repo.repo,
+            title: "Security Vulnerabilities Detected - Weekly Scan",
+            body: "Automated security scan has detected vulnerabilities. Please review the audit report and update dependencies accordingly.\n\nScan date: " + new Date().toISOString(),
+            labels: ["security", "automated"]
+          })
+
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
new file mode 100644
index 0000000000..46b5e5f3c1
--- /dev/null
+++ b/CONTRIBUTING.md
@@ -0,0 +1,208 @@
+# Contributing to HRM
+
+Thank you for your interest in contributing to the HRM (Heart Rate Monitor) project! This document provides guidelines and instructions for contributing to this project.
+
+## Development Setup
+
+1. **Clone the repository**
+   ```bash
+   git clone https://github.com/arii/hrm.git
+   cd hrm
+   ```
+
+2. **Install dependencies**
+   ```bash
+   npm install
+   ```
+
+3. **Set up environment variables**
+   ```bash
+   cp .env.example .env.local
+   # Edit .env.local with your configuration
+   ```
+
+4. **Start development server**
+   ```bash
+   npm run dev
+   ```
+
+## Code Style and Standards
+
+### TypeScript
+- Use strict TypeScript configuration
+- Prefer explicit types over `any`
+- Use interfaces for object shapes
+- Follow naming conventions (camelCase for variables, PascalCase for components)
+
+### React Components
+- Use functional components with hooks
+- Prefer named exports over default exports for components
+- Keep components small and focused
+- Use TypeScript for prop types
+
+### Code Formatting
+- We use Prettier for code formatting
+- ESLint for code linting
+- Run `npm run format` before committing
+- Run `npm run lint:fix` to fix linting issues
+
+## Testing
+
+### Running Tests
+```bash
+# Run all tests
+npm test
+
+# Run tests with coverage
+npm run test:coverage
+
+# Run tests in watch mode
+npm run test:watch
+
+# Run visual regression tests
+npm run test:visual
+```
+
+### Writing Tests
+- Write unit tests for utilities and hooks
+- Write integration tests for components
+- Aim for 70%+ code coverage
+- Use Testing Library best practices
+- Mock external dependencies appropriately
+
+## Commit Message Format
+
+We use [Conventional Commits](https://conventionalcommits.org/) format:
+
+```
+<type>[optional scope]: <description>
+
+[optional body]
+
+[optional footer(s)]
+```
+
+### Types:
+- `feat`: A new feature
+- `fix`: A bug fix
+- `docs`: Documentation only changes
+- `style`: Changes that do not affect the meaning of the code
+- `refactor`: A code change that neither fixes a bug nor adds a feature
+- `perf`: A code change that improves performance
+- `test`: Adding missing tests or correcting existing tests
+- `chore`: Changes to the build process or auxiliary tools
+
+### Examples:
+```
+feat(timer): add pause functionality to Tabata timer
+fix(websocket): resolve connection drop on network change
+docs: update API documentation for WebSocket events
+test: add unit tests for timer utilities
+```
+
+## Pull Request Process
+
+1. **Create a feature branch**
+   ```bash
+   git checkout -b feature/your-feature-name
+   ```
+
+2. **Make your changes**
+   - Write clean, well-documented code
+   - Add tests for new functionality
+   - Update documentation as needed
+
+3. **Test your changes**
+   ```bash
+   npm run lint
+   npm run test:coverage
+   npm run build
+   npm run test:visual
+   ```
+
+4. **Commit your changes**
+   ```bash
+   git add .
+   git commit -m "feat: your descriptive commit message"
+   ```
+
+5. **Push to your branch**
+   ```bash
+   git push origin feature/your-feature-name
+   ```
+
+6. **Create a Pull Request**
+   - Use the PR template
+   - Provide clear description of changes
+   - Link related issues
+   - Request appropriate reviewers
+
+## Code Review Process
+
+- All changes require review before merging
+- Address all review feedback
+- Ensure CI checks pass
+- Maintain code coverage thresholds
+- Update documentation for user-facing changes
+
+## Issue Reporting
+
+### Bug Reports
+- Use the bug report template
+- Provide clear reproduction steps
+- Include environment details
+- Attach screenshots if applicable
+
+### Feature Requests
+- Use the feature request template
+- Explain the problem being solved
+- Describe proposed solution
+- Consider implementation complexity
+
+## Release Process
+
+1. **Version Bumping**
+   - Follow semantic versioning (semver)
+   - Update CHANGELOG.md
+   - Update package.json version
+
+2. **Testing**
+   - Ensure all tests pass
+   - Run full regression testing
+   - Verify deployment builds
+
+3. **Documentation**
+   - Update README if needed
+   - Update API documentation
+   - Update migration guides
+
+## Getting Help
+
+- Join our development discussions in issues
+- Ask questions in pull request comments  
+- Review existing documentation and issues first
+
+## Code of Conduct
+
+- Be respectful and inclusive
+- Focus on what is best for the community
+- Show empathy towards other community members
+- Accept constructive criticism gracefully
+
+## Development Tools
+
+### Recommended VS Code Extensions
+- TypeScript and JavaScript Language Features
+- ESLint
+- Prettier
+- GitLens
+- Thunder Client (for API testing)
+
+### Git Workflow
+- Use descriptive branch names
+- Rebase feature branches before merging
+- Keep commits atomic and focused
+- Write meaningful commit messages
+
+Thank you for contributing to HRM! 🎉
+
diff --git a/test-proof.json b/test-proof.json
deleted file mode 100644
index 5fb04f13ce..0000000000
--- a/test-proof.json
+++ /dev/null
@@ -1,28 +0,0 @@
-{
-  "version": "1.0",
-  "timestamp": "2025-11-28T08:46:23.920Z",
-  "sourceHash": "70c0f15f519324ad863fe364df4f0b074e584244",
-  "status": "success",
-  "details": {
-    "infrastructure": {
-      "total": 4,
-      "passed": 4,
-      "failed": 0
-    },
-    "simple-smoke": {
-      "total": 1,
-      "passed": 1,
-      "failed": 0
-    },
-    "spotify-debug": {
-      "total": 2,
-      "passed": 2,
-      "failed": 0
-    },
-    "visual-regression": {
-      "total": 6,
-      "passed": 6,
-      "failed": 0
-    }
-  }
-}
\ No newline at end of file