feat: Notifiers CRUD (#337)

* introduce scaffold for new models

* wip: shoutrrr wrapper (may remove)

* update schema files

* gen: ent code

* gen: migrations

* go mod tidy

* add group_id to notifier

* db migration

* new mapper helpers

* notifier repo

* introduce experimental adapter pattern for hdlrs

* refactor adapters to fit more common use cases

* new routes for notifiers

* update errors to fix validation panic

* go tidy

* reverse checkbox label display

* wip: notifiers UI

* use badges instead of text

* improve documentation

* add scaffold schema reference

* remove notifier service

* refactor schema folder

* support group edges via scaffold

* delete test file

* include link to API docs

* audit and update documentation + improve format

* refactor schema edges

* refactor

* add custom validator

* set validate + order fields by name

* fix failing tests

backend/internal/web/adapters/actions.go

@@ -0,0 +1,74 @@
+package adapters
+
+import (
+	"net/http"
+
+	"github.com/hay-kot/homebox/backend/pkgs/server"
+)
+
+// Action is a function that adapts a function to the server.Handler interface.
+// It decodes the request body into a value of type T and passes it to the function f.
+// The function f is expected to return a value of type Y and an error.
+//
+// Example:
+//
+//	type Body struct {
+//	    Foo string `json:"foo"`
+//	}
+//
+//	fn := func(ctx context.Context, b Body) (any, error) {
+//	    // do something with b
+//	    return nil, nil
+//	}
+//
+// r.Post("/foo", adapters.Action(fn, http.StatusCreated))
+func Action[T any, Y any](f AdapterFunc[T, Y], ok int) server.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) error {
+		v, err := decode[T](r)
+		if err != nil {
+			return err
+		}
+
+		res, err := f(r.Context(), v)
+		if err != nil {
+			return err
+		}
+
+		return server.Respond(w, ok, res)
+	}
+}
+
+// ActionID functions the same as Action, but it also decodes a UUID from the URL path.
+//
+// Example:
+//
+//	type Body struct {
+//	    Foo string `json:"foo"`
+//	}
+//
+//	fn := func(ctx context.Context, ID uuid.UUID, b Body) (any, error) {
+//	    // do something with ID and b
+//	    return nil, nil
+//	}
+//
+//	r.Post("/foo/{id}", adapters.ActionID(fn, http.StatusCreated))
+func ActionID[T any, Y any](param string, f IDFunc[T, Y], ok int) server.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) error {
+		ID, err := routeUUID(r, param)
+		if err != nil {
+			return err
+		}
+
+		v, err := decode[T](r)
+		if err != nil {
+			return err
+		}
+
+		res, err := f(r.Context(), ID, v)
+		if err != nil {
+			return err
+		}
+
+		return server.Respond(w, ok, res)
+	}
+}