feat: phase 1 MVP — sections, services, drag-drop, renderers

Backend: migration 0002 (sections/items/urls/settings), CRUD +
fractional reorder, icon upload, settings, export/import, cached
status pings. Handler tests cover reorder, URL scheme validation,
settings round-trip.

Frontend: shared board store over the generated client, dnd-kit
layer (same-section, cross-section, section reorder persisted),
URL chooser popover, add/edit service dialog, settings dialog,
Bento + Cards renderers behind the shared seam, dark/light theme.

Generated with [Devin](https://devin.ai)

Authored By: TDvorak <[email protected]>
Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>

apps/backend/internal/api/transfer.go

@@ -0,0 +1,121 @@
+package api
+
+import (
+	"encoding/json"
+	"net/http"
+
+	"github.com/gin-gonic/gin"
+)
+
+// Export is the portable backup shape: version + settings + board tree.
+type Export struct {
+	Version  int                        `json:"version"`
+	Settings map[string]json.RawMessage `json:"settings"`
+	Sections []Section                  `json:"sections"`
+}
+
+func (s *Server) exportBoard(c *gin.Context) {
+	settings, err := s.allSettings()
+	if err != nil {
+		fail(c, http.StatusInternalServerError, err.Error())
+		return
+	}
+	sections, err := s.board()
+	if err != nil {
+		fail(c, http.StatusInternalServerError, err.Error())
+		return
+	}
+	c.JSON(http.StatusOK, Export{Version: 1, Settings: settings, Sections: sections})
+}
+
+// importBoard replaces board state inside one transaction. Ids from the
+// payload are preserved so a round-trip restores identical state.
+func (s *Server) importBoard(c *gin.Context) {
+	var in Export
+	if err := c.ShouldBindJSON(&in); err != nil || in.Sections == nil {
+		fail(c, http.StatusBadRequest, "invalid export payload")
+		return
+	}
+
+	tx, err := s.db.Begin()
+	if err != nil {
+		fail(c, http.StatusInternalServerError, err.Error())
+		return
+	}
+	defer func() { _ = tx.Rollback() }()
+
+	for _, q := range []string{`DELETE FROM urls`, `DELETE FROM items`, `DELETE FROM sections`} {
+		if _, err := tx.Exec(q); err != nil {
+			fail(c, http.StatusInternalServerError, err.Error())
+			return
+		}
+	}
+	for _, sec := range in.Sections {
+		if sec.ID == "" || sec.Name == "" {
+			fail(c, http.StatusBadRequest, "section missing id or name")
+			return
+		}
+		if _, err := tx.Exec(`INSERT INTO sections (id, name, position, collapsed) VALUES (?, ?, ?, ?)`,
+			sec.ID, sec.Name, sec.Position, sec.Collapsed); err != nil {
+			fail(c, http.StatusInternalServerError, err.Error())
+			return
+		}
+		for _, it := range sec.Items {
+			if it.ID == "" || it.Name == "" {
+				fail(c, http.StatusBadRequest, "item missing id or name")
+				return
+			}
+			var cfg any
+			if it.Config != nil {
+				cfg = string(*it.Config)
+			}
+			if _, err := tx.Exec(
+				`INSERT INTO items (id, section_id, kind, name, icon, position, config) VALUES (?, ?, ?, ?, ?, ?, ?)`,
+				it.ID, sec.ID, orDefault(it.Kind, "service"), it.Name, it.Icon, it.Position, cfg); err != nil {
+				fail(c, http.StatusInternalServerError, err.Error())
+				return
+			}
+			for _, u := range it.URLs {
+				if !validURL(u.URL) {
+					fail(c, http.StatusBadRequest, "invalid url: "+u.URL)
+					return
+				}
+				uid := u.ID
+				if uid == "" {
+					uid = newID("u")
+				}
+				if _, err := tx.Exec(`INSERT INTO urls (id, item_id, url, label, position) VALUES (?, ?, ?, ?, ?)`,
+					uid, it.ID, u.URL, u.Label, u.Position); err != nil {
+					fail(c, http.StatusInternalServerError, err.Error())
+					return
+				}
+			}
+		}
+	}
+	for k, v := range in.Settings {
+		if _, err := tx.Exec(
+			`INSERT INTO settings (key, value) VALUES (?, ?)
+			 ON CONFLICT(key) DO UPDATE SET value = excluded.value`, k, string(v)); err != nil {
+			fail(c, http.StatusInternalServerError, err.Error())
+			return
+		}
+	}
+	if err := tx.Commit(); err != nil {
+		fail(c, http.StatusInternalServerError, err.Error())
+		return
+	}
+
+	sections, err := s.board()
+	if err != nil {
+		fail(c, http.StatusInternalServerError, err.Error())
+		return
+	}
+	c.JSON(http.StatusOK, sections)
+}
+
+func orDefault(v, def string) string {
+	if v == "" {
+		return def
+	}
+	return v
+}