Refactor: share version-library grouping and bumpPatch

Extracts the per-key version grouping + same-version dedupe (org-owned shadows
builtin) into lib/versionedLibrary.groupVersions and the semver patch bump into
lib/semver.bumpPatch, both of which were duplicated byte-for-byte across the
Skills and Agent-profiles pages. One source of truth so the two libraries can't
drift.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

client/src/lib/semver.ts

@@ -0,0 +1,13 @@
+/** Bump the last numeric segment of a semver-ish string (1.0.0 → 1.0.1). Shared by the skill and
+ * agent-profile "new version" flows so the bump rule stays identical. */
+export function bumpPatch(version: string): string {
+  const parts = version.split('.')
+  for (let i = parts.length - 1; i >= 0; i--) {
+    const n = Number(parts[i])
+    if (Number.isInteger(n)) {
+      parts[i] = String(n + 1)
+      return parts.join('.')
+    }
+  }
+  return `${version}.1`
+}

client/src/lib/versionedLibrary.ts

@@ -0,0 +1,37 @@
+/**
+ * Shared grouping for the versioned libraries (skills and agent profiles). Both pages show one card
+ * per key with a version picker, and both must collapse a builtin that an org has forked at the same
+ * version — the org's own copy shadows the builtin (it's the one that resolves at run time and the
+ * one you can edit), keeping the picker unambiguous. Kept in one place so the two libraries can't drift.
+ */
+export interface VersionedItem {
+  version: string
+  origin: string
+}
+
+/** Group items by key, dedupe per version (org-owned shadows builtin), and sort keys alphabetically. */
+export function groupVersions<T extends VersionedItem>(
+  items: T[],
+  keyOf: (item: T) => string,
+): [string, T[]][] {
+  const byKey = new Map<string, T[]>()
+  for (const item of items) {
+    const key = keyOf(item)
+    const list = byKey.get(key) ?? []
+    list.push(item)
+    byKey.set(key, list)
+  }
+
+  for (const [key, list] of byKey) {
+    const perVersion = new Map<string, T>()
+    for (const item of list) {
+      const existing = perVersion.get(item.version)
+      if (!existing || (existing.origin === 'Builtin' && item.origin !== 'Builtin')) {
+        perVersion.set(item.version, item)
+      }
+    }
+    byKey.set(key, [...perVersion.values()])
+  }
+
+  return [...byKey.entries()].sort((a, b) => a[0].localeCompare(b[0]))
+}