update the workspace and skills flow

src/lib/skills/surfaces.js

@@ -438,6 +438,7 @@ export const DATA_SOURCES = [
     context: 'positionId',
     summary: 'Applications to this position, counted over time.',
     shapes: ['flow', 'stats', 'timeline', 'table', 'insight', 'card'],
+    options: ['periods'],
   },
   {
     id: 'position.pipeline',
@@ -452,6 +453,7 @@ export const DATA_SOURCES = [
     context: 'positionId',
     summary: 'Candidates matched to this position, best first.',
     shapes: ['list', 'table', 'stats', 'card'],
+    options: ['limit'],
   },
   {
     /**
@@ -469,6 +471,7 @@ export const DATA_SOURCES = [
     context: 'positionId',
     summary: 'The candidate pool scored against this position, best first.',
     shapes: ['list', 'table', 'stats', 'card', 'insight'],
+    options: ['limit'],
   },
   {
     id: 'position.requirements',
@@ -504,6 +507,7 @@ export const DATA_SOURCES = [
     context: null,
     summary: 'Applications across the workspace, counted over time.',
     shapes: ['flow', 'stats', 'timeline', 'table', 'card'],
+    options: ['periods'],
   },
   {
     id: 'positions.demand',
@@ -511,6 +515,7 @@ export const DATA_SOURCES = [
     context: null,
     summary: 'Open positions and what they still need.',
     shapes: ['list', 'table', 'stats', 'card'],
+    options: ['limit'],
   },
   {
     id: 'workforce.training',
@@ -518,6 +523,7 @@ export const DATA_SOURCES = [
     context: null,
     summary: 'Training paths and progress against them.',
     shapes: ['progress', 'list', 'stats', 'table', 'card'],
+    options: ['limit'],
   },
   {
     /* The vetting weights a position is being specified with. `positionId`
@@ -548,6 +554,7 @@ export const DATA_SOURCES = [
     context: null,
     summary: 'Who was hired, for which role, and when.',
     shapes: ['list', 'table', 'timeline', 'stats', 'card'],
+    options: ['limit'],
   },
   {
     id: 'hires.performance',
@@ -562,6 +569,7 @@ export const DATA_SOURCES = [
     context: null,
     summary: 'What has happened across the workspace, most recent first.',
     shapes: ['timeline', 'list', 'table', 'stats', 'card'],
+    options: ['limit'],
   },
 ];
 
@@ -569,6 +577,60 @@ export const SUPPORTED_DATA_SOURCES = DATA_SOURCES.map((s) => s.id);
 
 export const dataSourceFor = (id) => DATA_SOURCES.find((s) => s.id === id) || null;
 
+/* ── Source / shape compatibility ───────────────────────────────────────────
+   One resolver, three consumers: `normalizeSection` refuses on it, the Board
+   editor's source picker filters on it, and the Owliver editor's per-capability
+   picker filters on it. They used to be three readings of `source.shapes` —
+   inline in the normalizer, absent from one editor and approximated in the
+   other — which is how a form could compose `list` against a source that has no
+   list in it and only find out at save. */
+
+/**
+ * The section type a capability is drawn with, or null when it is prose.
+ *
+ * `summary` is the one capability with no component, so it is compatible with
+ * every source: the figures are read back as sentences rather than drawn.
+ */
+export const shapeForCapability = (capability) => owliverCapabilityFor(capability)?.shape || null;
+
+/** Can this source be drawn as this shape? A null shape is prose, and always can. */
+export function sourceSupportsShape(sourceId, shape) {
+  const source = dataSourceFor(sourceId);
+  if (!source) return false;
+  if (!shape) return true;
+  return Boolean(source.shapes?.includes(shape));
+}
+
+/**
+ * The sources that can fill this shape, optionally narrowed to what a placement
+ * can supply context for.
+ *
+ * `context` is the list a placement provides — `contextSuppliedBy(pages,
+ * placement)`. Passing it is how the Board editor offers only sources that can
+ * actually resolve where the section is mounted; the Owliver editor passes
+ * nothing, because a response with an unmet need asks which record is meant
+ * rather than rendering dead.
+ */
+export function sourcesForShape(shape, { context = null } = {}) {
+  return DATA_SOURCES.filter((source) => {
+    if (!sourceSupportsShape(source.id, shape)) return false;
+    if (!context) return true;
+    return !source.context || context.includes(source.context);
+  });
+}
+
+/**
+ * Whether a source reads an option a form can offer — `periods` or `limit`.
+ *
+ * Declared per source rather than inferred from its shapes, because the two do
+ * not line up: `positions.demand` is a list that honours `limit` and has no
+ * periods at all, while `candidates.activity` is the reverse. The editors used
+ * to guess from the shape list and offered period checkboxes that changed
+ * nothing.
+ */
+export const sourceSupportsOption = (sourceId, option) =>
+  Boolean(dataSourceFor(sourceId)?.options?.includes(option));
+
 /**
  * Can this reading be written back?
  *