feat: implement main application structure with UI and layout management

- Added main application logic in `src/ui/app.rs` to handle state and modal dialogs.
- Created module structure for UI components in `src/ui/mod.rs`.
- Implemented column configuration screen in `src/ui/screens/configuracao_colunas.rs`.
- Developed file import screen in `src/ui/screens/import.rs` for CSV and XLSX files.
- Added layout management screen in `src/ui/screens/layouts.rs` for saving and importing layouts.
- Created result display screen in `src/ui/screens/resultado.rs` to show analysis results.
- Introduced modular organization for screens in `src/ui/screens/mod.rs`.

src/infrastructure/sqlite/migrations.rs

@@ -0,0 +1,62 @@
+use rusqlite::{Connection, Result};
+
+/// Versão atual do schema do banco de dados.
+const VERSAO_SCHEMA_ATUAL: i64 = 1;
+
+/// Aplica todas as migrations necessárias para atualizar o banco
+/// para a versão mais recente.
+pub fn aplicar_migrations(conn: &Connection) -> Result<()> {
+    // Criar tabela de controle de versão se não existir
+    conn.execute_batch(
+        "CREATE TABLE IF NOT EXISTS schema_version (
+            versao INTEGER NOT NULL
+        );",
+    )?;
+
+    let versao_atual: i64 = conn
+        .query_row(
+            "SELECT versao FROM schema_version LIMIT 1;",
+            [],
+            |row| row.get(0),
+        )
+        .unwrap_or(0);
+
+    if versao_atual < 1 {
+        migration_v1(conn)?;
+        if versao_atual == 0 {
+            conn.execute("INSERT INTO schema_version (versao) VALUES (?1);", [1])?;
+        } else {
+            conn.execute("UPDATE schema_version SET versao = ?1;", [1])?;
+        }
+    }
+
+    Ok(())
+}
+
+/// Migration v1: criar tabela de layouts.
+fn migration_v1(conn: &Connection) -> Result<()> {
+    conn.execute_batch(
+        "CREATE TABLE IF NOT EXISTS layouts (
+            id               INTEGER PRIMARY KEY AUTOINCREMENT,
+            nome             TEXT NOT NULL,
+            tipo             TEXT NOT NULL CHECK(tipo IN ('csv', 'xlsx')),
+
+            -- Campos CSV
+            delimitador      TEXT,
+            encoding         TEXT,
+            linha_cabecalho  INTEGER,
+            indice_numero    INTEGER,
+            indice_serie     INTEGER,
+            indice_valor     INTEGER,
+            indice_data      INTEGER,
+
+            -- Campos XLSX
+            aba              TEXT,
+            pos_numero       TEXT,
+            pos_serie        TEXT,
+            pos_valor        TEXT,
+            pos_data         TEXT
+        );",
+    )?;
+    Ok(())
+}