Commit rest of changes

.gitignore

@@ -15,6 +15,10 @@
 # Output of the go coverage tool, specifically when used with LiteIDE
 *.out
 
+# Backup files
+*.bak
+
+
 # Dependency directories (remove the comment below to include it)
 # vendor/
 

internal/storage/migrations/001_initial.sql

@@ -0,0 +1,36 @@
+-- sessions table stores high-level chat session metadata.
+CREATE TABLE IF NOT EXISTS sessions (
+    id INTEGER PRIMARY KEY AUTOINCREMENT,
+    name TEXT NOT NULL,
+    created_at DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    updated_at DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    model_name TEXT NOT NULL,
+    summary TEXT
+);
+
+CREATE UNIQUE INDEX IF NOT EXISTS idx_sessions_name ON sessions(name);
+
+-- messages table stores individual conversation messages linked to sessions.
+CREATE TABLE IF NOT EXISTS messages (
+    id INTEGER PRIMARY KEY AUTOINCREMENT,
+    session_id INTEGER NOT NULL,
+    role TEXT NOT NULL,
+    content TEXT NOT NULL,
+    token_count INTEGER,
+    created_at DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    FOREIGN KEY(session_id) REFERENCES sessions(id) ON DELETE CASCADE
+);
+
+CREATE INDEX IF NOT EXISTS idx_messages_session_created_at ON messages(session_id, created_at);
+
+-- models table tracks available models and usage metadata.
+CREATE TABLE IF NOT EXISTS models (
+    id INTEGER PRIMARY KEY AUTOINCREMENT,
+    name TEXT NOT NULL,
+    display_name TEXT,
+    provider TEXT,
+    is_default BOOLEAN NOT NULL DEFAULT 0,
+    last_used_at DATETIME
+);
+
+CREATE UNIQUE INDEX IF NOT EXISTS idx_models_name ON models(name);

internal/storage/storage.go

@@ -4,9 +4,11 @@ import (
 	"database/sql"
 	"errors"
 	"fmt"
+	"io/fs"
 	"os"
 	"path/filepath"
 	"runtime"
+	"sort"
 	"strings"
 	"sync"
 
@@ -57,6 +59,11 @@ func (m *Manager) Open() (*sql.DB, error) {
 		return nil, fmt.Errorf("ping sqlite: %w", err)
 	}
 
+	if err := applyMigrations(db); err != nil {
+		_ = db.Close()
+		return nil, err
+	}
+
 	m.db = db
 	return db, nil
 }
@@ -112,3 +119,49 @@ func ensureDir(dir string) error {
 
 	return nil
 }
+
+func applyMigrations(db *sql.DB) error {
+	migrationsFS := os.DirFS("internal/storage/migrations")
+
+	entries, err := fs.ReadDir(migrationsFS, ".")
+	if err != nil {
+		return fmt.Errorf("read migrations: %w", err)
+	}
+
+	var files []string
+	for _, entry := range entries {
+		if entry.IsDir() {
+			continue
+		}
+		if filepath.Ext(entry.Name()) != ".sql" {
+			continue
+		}
+		files = append(files, entry.Name())
+	}
+
+	sort.Strings(files)
+
+	tx, err := db.Begin()
+	if err != nil {
+		return fmt.Errorf("begin migration tx: %w", err)
+	}
+
+	for _, name := range files {
+		data, readErr := fs.ReadFile(migrationsFS, name)
+		if readErr != nil {
+			_ = tx.Rollback()
+			return fmt.Errorf("read migration %s: %w", name, readErr)
+		}
+
+		if _, execErr := tx.Exec(string(data)); execErr != nil {
+			_ = tx.Rollback()
+			return fmt.Errorf("apply migration %s: %w", name, execErr)
+		}
+	}
+
+	if err := tx.Commit(); err != nil {
+		return fmt.Errorf("commit migrations: %w", err)
+	}
+
+	return nil
+}