Add tm_server with SQLite, Svelte UI, and task-master TUI sync.

Introduces the web backend (auth, RBAC, project tokens, revisions),
YouTrack-or-taskmaster backend choice in the TUI, and a first-pass
embedded Svelte UI. The frontend is functional but needs a major rework.

Co-authored-by: Cursor <cursoragent@cursor.com>

internal/sqlite/connections.go

@@ -0,0 +1,118 @@
+package sqlite
+
+import (
+	"database/sql"
+	"fmt"
+	"strings"
+	"time"
+
+	"github.com/google/uuid"
+)
+
+// Connection is a remote backend credential (instance or project scope).
+type Connection struct {
+	ID        string    `json:"id"`
+	Name      string    `json:"name"`
+	Kind      string    `json:"kind"`
+	BaseURL   string    `json:"baseUrl"`
+	Scope     string    `json:"scope"` // instance | project
+	CreatedBy string    `json:"createdBy"`
+	CreatedAt time.Time `json:"createdAt"`
+	Token     string    `json:"-"` // only populated when decrypted for sync
+}
+
+// CreateConnection stores an encrypted token.
+func (db *DB) CreateConnection(name, kind, baseURL, scope, token, createdBy string) (Connection, error) {
+	name = strings.TrimSpace(name)
+	kind = strings.TrimSpace(kind)
+	baseURL = strings.TrimSpace(baseURL)
+	scope = strings.TrimSpace(scope)
+	if name == "" || kind == "" || baseURL == "" || token == "" {
+		return Connection{}, fmt.Errorf("name, kind, baseUrl and token required")
+	}
+	if scope == "" {
+		scope = "instance"
+	}
+	enc, err := db.EncryptToken(token)
+	if err != nil {
+		return Connection{}, err
+	}
+	c := Connection{
+		ID:        uuid.NewString(),
+		Name:      name,
+		Kind:      kind,
+		BaseURL:   baseURL,
+		Scope:     scope,
+		CreatedBy: createdBy,
+		CreatedAt: time.Now().UTC(),
+	}
+	_, err = db.SQL.Exec(`
+		INSERT INTO connections(id, name, kind, base_url, scope, encrypted_token, created_by, created_at)
+		VALUES(?,?,?,?,?,?,?,?)`,
+		c.ID, c.Name, c.Kind, c.BaseURL, c.Scope, enc, c.CreatedBy, formatTime(c.CreatedAt))
+	if err != nil {
+		return Connection{}, err
+	}
+	return c, nil
+}
+
+// ListConnections returns connections without tokens.
+func (db *DB) ListConnections() ([]Connection, error) {
+	rows, err := db.SQL.Query(`
+		SELECT id, name, kind, base_url, scope, created_by, created_at
+		FROM connections ORDER BY name COLLATE NOCASE`)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+	var out []Connection
+	for rows.Next() {
+		var c Connection
+		var created string
+		if err := rows.Scan(&c.ID, &c.Name, &c.Kind, &c.BaseURL, &c.Scope, &c.CreatedBy, &created); err != nil {
+			return nil, err
+		}
+		c.CreatedAt = parseTime(created)
+		out = append(out, c)
+	}
+	if out == nil {
+		out = []Connection{}
+	}
+	return out, rows.Err()
+}
+
+// GetConnection loads a connection and decrypts its token.
+func (db *DB) GetConnection(id string) (Connection, error) {
+	var c Connection
+	var created string
+	var blob []byte
+	err := db.SQL.QueryRow(`
+		SELECT id, name, kind, base_url, scope, encrypted_token, created_by, created_at
+		FROM connections WHERE id = ?`, id).
+		Scan(&c.ID, &c.Name, &c.Kind, &c.BaseURL, &c.Scope, &blob, &c.CreatedBy, &created)
+	if err == sql.ErrNoRows {
+		return Connection{}, fmt.Errorf("connection %s: not found", id)
+	}
+	if err != nil {
+		return Connection{}, err
+	}
+	c.CreatedAt = parseTime(created)
+	c.Token, err = db.DecryptToken(blob)
+	if err != nil {
+		return Connection{}, err
+	}
+	return c, nil
+}
+
+// DeleteConnection removes a connection.
+func (db *DB) DeleteConnection(id string) error {
+	res, err := db.SQL.Exec(`DELETE FROM connections WHERE id = ?`, id)
+	if err != nil {
+		return err
+	}
+	n, _ := res.RowsAffected()
+	if n == 0 {
+		return fmt.Errorf("connection %s: not found", id)
+	}
+	return nil
+}