feat(projects): drag the sidebar into the order you want

Projects have carried sort_order since the first migration and nothing
ever set it, so the sidebar was ordered by creation date for good.

POST /projects/reorder takes the whole list rather than one move. A
person has a handful of projects, so sending the order you want is
simpler to reason about than midpoints between neighbours — and it cannot
run out of precision, which is the failure the task ordering has to
respace a section to recover from. It also cannot land half-applied the
way a sequence of individual moves can.

Projects you do not own are skipped rather than refused. sort_order is a
column on the project, not a preference per viewer, so a shared project
sits where its owner put it and a member rearranging their own sidebar
does not rearrange somebody else's. The sidebar only makes your own
projects draggable, so that rule never shows up as a row that springs
back.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

web/src/lib/api.js

@@ -176,6 +176,7 @@ export const api = {
 	createProject: (data) => post('/projects', data),
 	updateProject: (id, data) => patch(`/projects/${id}`, data),
 	deleteProject: (id) => del(`/projects/${id}`),
+	reorderProjects: (ids) => post('/projects/reorder', { ids }),
 	listTrashedProjects: () => get('/trash/projects'),
 	restoreProject: (id) => post(`/trash/projects/${id}/restore`),