feat(defects): file a defect via a board-section modal (T5)

POST /api/defects validates the body with arktype (known section, uuid
project, non-empty trimmed verbatim) and resolves the reporter through a dev
seam (getReporter, ADR 0002) until OAuth lands. DefectForm is a DaisyUI modal
opened by a section click — pick a project, describe the problem, submit.

server/utils/defectInput.ts

@@ -0,0 +1,17 @@
+import { type } from 'arktype'
+import { sectionIds } from '../../app/board/definition'
+
+// Validated request body for filing a defect (F2). The reporter is resolved
+// server-side via the session seam, never trusted from the client. Verbatim is
+// trimmed; the section must be one defined on the canonical board (C1).
+export const DefectInput = type({
+  sectionId: type('string').narrow(
+    (id, ctx) => sectionIds.has(id) || ctx.reject('a known board section id'),
+  ),
+  projectId: 'string.uuid',
+  verbatim: type('string')
+    .pipe((s) => s.trim())
+    .narrow((s, ctx) => s.length > 0 || ctx.reject('non-empty text')),
+})
+
+export type DefectInputData = typeof DefectInput.infer