The flow editor can now change a flow's shape on the canvas, not only
through the inspector's fields:
- drag a box onto another to move it and its branch there; a drop the
save would refuse shows the target dashed red and gives the reason;
- a palette of node kinds adds a node below the picked box on click, or
below any box it is dragged onto; it offers what the controller lists;
- arrow keys walk the tree, M picks a box up and Enter drops it under
the focused one, Alt+Up/Down reorder a node among its siblings, Delete
removes a branch; focus follows the edit;
- each box with siblings says when it runs, and the inspector can move
it earlier or later, since the router runs children in edge order;
- request_reviewer is a second leaf kind beside todo, with a reviewer
field;
- leaving with unsaved edits asks first, also for in-app links and the
back button (a router hook runs navigation past a page's guard).
A custom flow opens at /notifications/<id>: its nodes drawn left to right
(source, then matches, then todos), and a panel to edit the picked node: the
source's events, a match's conditions, a todo's recipients, op, key and text.
Add a match or todo below a node, move a branch under another match, or remove
it; an edit the controller would refuse (a todo with children, a second
parent, a cycle, over the node or depth cap) is turned away with the reason.
Edits stay in a draft until save, which sends the whole document at the
revision read. A stale revision is told apart from a refused document: the
editor offers to reload or to keep the draft on top of the latest. The form
choices come from the controller's schema when it sends one.
The list page gains edit and duplicate on custom flows, duplicate on the
built-ins, and a new-flow box; a new flow's id avoids the built-ins' too.
