feat: add JSON API with token auth (closes #69)

- Add API token model with SHA-256 hashed tokens
- Add migration 006_add_api_tokens.sql
- Add Bearer token auth middleware
- Add API endpoints under /api/v1/:
  - GET /whoami
  - POST /tokens (create new API token)
  - GET /apps (list all apps)
  - POST /apps (create app)
  - GET /apps/{id} (get app)
  - DELETE /apps/{id} (delete app)
  - POST /apps/{id}/deploy (trigger deployment)
  - GET /apps/{id}/deployments (list deployments)
- Add comprehensive tests for all API endpoints
- All tests pass, zero lint issues

internal/models/api_token.go

@@ -0,0 +1,187 @@
+package models
+
+import (
+	"context"
+	"crypto/rand"
+	"crypto/sha256"
+	"database/sql"
+	"encoding/hex"
+	"errors"
+	"fmt"
+	"time"
+
+	"git.eeqj.de/sneak/upaas/internal/database"
+)
+
+// tokenBytes is the number of random bytes for a raw API token.
+const tokenBytes = 32
+
+// APIToken represents an API authentication token.
+type APIToken struct {
+	db *database.Database
+
+	ID         int64
+	UserID     int64
+	Name       string
+	TokenHash  string
+	CreatedAt  time.Time
+	LastUsedAt sql.NullTime
+}
+
+// NewAPIToken creates a new APIToken with a database reference.
+func NewAPIToken(db *database.Database) *APIToken {
+	return &APIToken{db: db}
+}
+
+// GenerateAPIToken creates a new API token for a user, returning the raw token
+// string (shown once) and the persisted APIToken record.
+func GenerateAPIToken(
+	ctx context.Context,
+	db *database.Database,
+	userID int64,
+	name string,
+) (string, *APIToken, error) {
+	raw := make([]byte, tokenBytes)
+
+	_, err := rand.Read(raw)
+	if err != nil {
+		return "", nil, fmt.Errorf("generating token bytes: %w", err)
+	}
+
+	rawHex := hex.EncodeToString(raw)
+	hash := HashAPIToken(rawHex)
+
+	token := NewAPIToken(db)
+	token.UserID = userID
+	token.Name = name
+	token.TokenHash = hash
+
+	query := `INSERT INTO api_tokens (user_id, name, token_hash) VALUES (?, ?, ?)`
+
+	result, execErr := db.Exec(ctx, query, userID, name, hash)
+	if execErr != nil {
+		return "", nil, fmt.Errorf("inserting api token: %w", execErr)
+	}
+
+	id, idErr := result.LastInsertId()
+	if idErr != nil {
+		return "", nil, fmt.Errorf("getting token id: %w", idErr)
+	}
+
+	token.ID = id
+
+	reloadErr := token.Reload(ctx)
+	if reloadErr != nil {
+		return "", nil, fmt.Errorf("reloading token: %w", reloadErr)
+	}
+
+	return rawHex, token, nil
+}
+
+// HashAPIToken returns the SHA-256 hex digest of a raw token string.
+func HashAPIToken(raw string) string {
+	sum := sha256.Sum256([]byte(raw))
+
+	return hex.EncodeToString(sum[:])
+}
+
+// Reload refreshes the token from the database.
+func (t *APIToken) Reload(ctx context.Context) error {
+	row := t.db.QueryRow(ctx,
+		`SELECT id, user_id, name, token_hash, created_at, last_used_at
+		 FROM api_tokens WHERE id = ?`, t.ID,
+	)
+
+	return t.scan(row)
+}
+
+// Delete removes the token from the database.
+func (t *APIToken) Delete(ctx context.Context) error {
+	_, err := t.db.Exec(ctx, "DELETE FROM api_tokens WHERE id = ?", t.ID)
+
+	return err
+}
+
+// TouchLastUsed updates the last_used_at timestamp.
+func (t *APIToken) TouchLastUsed(ctx context.Context) error {
+	_, err := t.db.Exec(ctx,
+		"UPDATE api_tokens SET last_used_at = CURRENT_TIMESTAMP WHERE id = ?",
+		t.ID,
+	)
+
+	return err
+}
+
+func (t *APIToken) scan(row *sql.Row) error {
+	return row.Scan(
+		&t.ID, &t.UserID, &t.Name, &t.TokenHash,
+		&t.CreatedAt, &t.LastUsedAt,
+	)
+}
+
+// FindAPITokenByHash looks up a token by its SHA-256 hash.
+//
+//nolint:nilnil // returning nil,nil is idiomatic for "not found" in Active Record
+func FindAPITokenByHash(
+	ctx context.Context,
+	db *database.Database,
+	hash string,
+) (*APIToken, error) {
+	token := NewAPIToken(db)
+
+	row := db.QueryRow(ctx,
+		`SELECT id, user_id, name, token_hash, created_at, last_used_at
+		 FROM api_tokens WHERE token_hash = ?`, hash,
+	)
+
+	err := token.scan(row)
+	if err != nil {
+		if errors.Is(err, sql.ErrNoRows) {
+			return nil, nil
+		}
+
+		return nil, fmt.Errorf("scanning api token: %w", err)
+	}
+
+	return token, nil
+}
+
+// FindAPITokensByUserID returns all tokens for a user.
+func FindAPITokensByUserID(
+	ctx context.Context,
+	db *database.Database,
+	userID int64,
+) ([]*APIToken, error) {
+	rows, err := db.Query(ctx,
+		`SELECT id, user_id, name, token_hash, created_at, last_used_at
+		 FROM api_tokens WHERE user_id = ? ORDER BY created_at DESC`, userID,
+	)
+	if err != nil {
+		return nil, fmt.Errorf("querying api tokens: %w", err)
+	}
+
+	defer func() { _ = rows.Close() }()
+
+	var tokens []*APIToken
+
+	for rows.Next() {
+		tok := NewAPIToken(db)
+
+		scanErr := rows.Scan(
+			&tok.ID, &tok.UserID, &tok.Name, &tok.TokenHash,
+			&tok.CreatedAt, &tok.LastUsedAt,
+		)
+		if scanErr != nil {
+			return nil, fmt.Errorf("scanning api token row: %w", scanErr)
+		}
+
+		tokens = append(tokens, tok)
+	}
+
+	rowsErr := rows.Err()
+	if rowsErr != nil {
+		return nil, fmt.Errorf("iterating api token rows: %w", rowsErr)
+	}
+
+	return tokens, nil
+}