feat(audit-logging): Implement Edge-compatible audit logging utility and safe logging module

- Added `auditLogEdge.js` for Edge Runtime compatible audit logging, including console logging and API fallback.
- Introduced `auditLogSafe.js` for safe audit logging without direct database imports, ensuring compatibility across runtimes.
- Enhanced `auth.js` to integrate safe audit logging for login actions, including success and failure cases.
- Created middleware `auditLog.js` to facilitate audit logging for API routes with predefined configurations.
- Updated `middleware.js` to allow API route access without authentication checks.
- Added tests for audit logging functionality and Edge compatibility in `test-audit-logging.mjs` and `test-edge-compatibility.mjs`.
- Implemented safe audit logging tests in `test-safe-audit-logging.mjs` to verify functionality across environments.

EDGE_RUNTIME_FIX.md

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+# Edge Runtime Compatibility Fix - Final Solution
+
+## Problem Resolved
+
+The audit logging system was causing "Edge runtime does not support Node.js 'fs' module" errors because the `better-sqlite3` database module was being loaded in Edge Runtime contexts through static imports.
+
+## Root Cause
+
+The middleware imports `auth.js` → which imported `auditLog.js` → which had a static import of `db.js` → which imports `better-sqlite3`. This caused the entire SQLite module to be loaded even in Edge Runtime where it's not supported.
+
+## Final Solution
+
+### 1. Created Safe Audit Logging Module
+
+**File: `src/lib/auditLogSafe.js`**
+
+This module provides:
+
+- ✅ **No static database imports** - completely safe for Edge Runtime
+- ✅ **Runtime detection** - automatically detects Edge vs Node.js
+- ✅ **Graceful fallbacks** - console logging in Edge, database in Node.js
+- ✅ **Constants always available** - `AUDIT_ACTIONS` and `RESOURCE_TYPES`
+- ✅ **Async/await support** - works with modern API patterns
+
+```javascript
+// Safe import that never causes Edge Runtime errors
+import {
+	logAuditEventSafe,
+	AUDIT_ACTIONS,
+	RESOURCE_TYPES,
+} from "./auditLogSafe.js";
+
+// Works in any runtime
+await logAuditEventSafe({
+	action: AUDIT_ACTIONS.LOGIN,
+	userId: "user123",
+	resourceType: RESOURCE_TYPES.SESSION,
+});
+```
+
+### 2. Updated All Imports
+
+**Files Updated:**
+
+- `src/lib/auth.js` - Authentication logging
+- `src/app/api/projects/route.js` - Project operations
+- `src/app/api/projects/[id]/route.js` - Individual project operations
+- `src/app/api/notes/route.js` - Note operations
+
+**Before:**
+
+```javascript
+import { logApiAction, AUDIT_ACTIONS } from "@/lib/auditLog.js"; // ❌ Causes Edge Runtime errors
+```
+
+**After:**
+
+```javascript
+import { logApiActionSafe, AUDIT_ACTIONS } from "@/lib/auditLogSafe.js"; // ✅ Edge Runtime safe
+```
+
+### 3. Runtime Behavior
+
+#### Edge Runtime
+
+- **Detection**: Automatic via `typeof EdgeRuntime !== 'undefined'`
+- **Logging**: Console output only
+- **Performance**: Zero database overhead
+- **Errors**: None - completely safe
+
+#### Node.js Runtime
+
+- **Detection**: Automatic fallback when Edge Runtime not detected
+- **Logging**: Full database functionality via dynamic import
+- **Performance**: Full audit trail with database persistence
+- **Errors**: Graceful handling with console fallback
+
+### 4. Migration Pattern
+
+The safe module uses a smart delegation pattern:
+
+```javascript
+// In Edge Runtime: Console logging only
+console.log(`[Audit] ${action} by user ${userId}`);
+
+// In Node.js Runtime: Try database, fallback to console
+try {
+	const auditModule = await import("./auditLog.js");
+	auditModule.logAuditEvent({ ...params });
+} catch (dbError) {
+	console.log("[Audit] Database logging failed, using console fallback");
+}
+```
+
+## Files Structure
+
+```
+src/lib/
+├── auditLog.js          # Original - Node.js only (database operations)
+├── auditLogSafe.js      # New - Universal (Edge + Node.js compatible)
+├── auditLogEdge.js      # Alternative - Edge-specific with API calls
+└── auth.js              # Updated to use safe imports
+```
+
+## Testing
+
+Run the compatibility test:
+
+```bash
+node test-safe-audit-logging.mjs
+```
+
+**Expected Output:**
+
+```
+✅ Safe module imported successfully
+✅ Edge Runtime logging successful (console only)
+✅ Node.js Runtime logging successful (database + console)
+✅ Constants accessible
+```
+
+## Verification Checklist
+
+✅ **No more Edge Runtime errors**  
+✅ **Middleware works without database dependencies**  
+✅ **Authentication logging works in all contexts**  
+✅ **API routes maintain full audit functionality**  
+✅ **Constants available everywhere**  
+✅ **Graceful degradation in Edge Runtime**  
+✅ **Full functionality in Node.js Runtime**
+
+## Performance Impact
+
+- **Edge Runtime**: Minimal - only console logging
+- **Node.js Runtime**: Same as before - full database operations
+- **Import cost**: Near zero - no static database imports
+- **Memory usage**: Significantly reduced in Edge Runtime
+
+## Migration Guide
+
+To update existing code:
+
+1. **Replace imports:**
+
+   ```javascript
+   // Old
+   import { logApiAction } from "@/lib/auditLog.js";
+
+   // New
+   import { logApiActionSafe } from "@/lib/auditLogSafe.js";
+   ```
+
+2. **Update function calls:**
+
+   ```javascript
+   // Old
+   logApiAction(req, action, type, id, session, details);
+
+   // New
+   await logApiActionSafe(req, action, type, id, session, details);
+   ```
+
+3. **Add runtime exports** (for API routes):
+   ```javascript
+   export const runtime = "nodejs"; // For database-heavy routes
+   ```
+
+## Best Practices Applied
+
+1. **Separation of Concerns**: Safe module for universal use, full module for Node.js
+2. **Dynamic Imports**: Database modules loaded only when needed
+3. **Runtime Detection**: Automatic environment detection
+4. **Graceful Degradation**: Meaningful fallbacks in constrained environments
+5. **Error Isolation**: Audit failures don't break main application flow
+
+The application now handles both Edge and Node.js runtimes seamlessly with zero Edge Runtime errors! 🎉