Fix database encryption write operations and initialization

This commit fixes critical issues with the database encryption system:

**Database Write Operations Fixed:**
- Modified credential creation/update operations to use EncryptedDBOperations
- Fixed SSH data and credential access to properly decrypt data
- All sensitive data writes now go through encryption layer

**Database Schema Migration:**
- Added missing columns (private_key, public_key, detected_key_type) to ssh_credentials table
- Fixed "no such column" SQLite errors during encrypted operations

**Application Startup Order:**
- Fixed DatabaseEncryption initialization timing issues
- Moved encryption-dependent modules to load after encryption initialization
- Prevents "DatabaseEncryption not initialized" errors

**Key Management Improvements:**
- Enhanced EncryptedDBOperations.insert() to return properly decrypted data with all fields
- Fixed TypeScript type issues with database insert operations
- Improved error handling for database encryption context

All credential operations now properly encrypt sensitive data including SSH keys,
passwords, and authentication tokens before writing to database.

src/backend/database/db/index.ts

@@ -250,6 +250,11 @@ const migrateSchema = () => {
     "INTEGER REFERENCES ssh_credentials(id)",
   );
 
+  // SSH credentials table migrations for encryption support
+  addColumnIfNotExists("ssh_credentials", "private_key", "TEXT");
+  addColumnIfNotExists("ssh_credentials", "public_key", "TEXT");
+  addColumnIfNotExists("ssh_credentials", "detected_key_type", "TEXT");
+
   addColumnIfNotExists("file_manager_recent", "host_id", "INTEGER NOT NULL");
   addColumnIfNotExists("file_manager_pinned", "host_id", "INTEGER NOT NULL");
   addColumnIfNotExists("file_manager_shortcuts", "host_id", "INTEGER NOT NULL");