fix: Update SQLite driver name from 'sqlite3' to 'sqlite'

The modernc.org/sqlite package registers its driver as 'sqlite', not 'sqlite3'.
Updated the sql.Open() call to use the correct driver name.

This fixes the database connection error:
'sql: unknown driver "sqlite3" (forgotten import?)'

Verified working:
- Database initialization succeeds
- skyview-data status command works
- Main skyview server starts with database connection

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

internal/database/database.go

@@ -144,7 +144,7 @@ func NewDatabase(config *Config) (*Database, error) {
 	config.Path = dbPath
 
 	// Open database connection
-	conn, err := sql.Open("sqlite3", buildConnectionString(dbPath))
+	conn, err := sql.Open("sqlite", buildConnectionString(dbPath))
 	if err != nil {
 		return nil, &DatabaseError{
 			Operation: "connect",