fix(spec): the per-item publish's packageId description carries the save's no-package-unbound-draft qualifier

Description only.

Claude-Session: https://claude.ai/code/session_01HTBbFnY86QT5g7BxeMo3Ub
Co-authored-by: Claude <noreply@anthropic.com>

Author: claude

packages/spec/src/api/protocol.zod.ts

@@ -1056,7 +1056,8 @@ export const PublishMetaItemRequestSchema = lazySchema(() => z.object({
     + 'exists, as the strict draft read does. For an item never published into '
     + 'a package it is the package-unbound draft, else the one package\'s '
     + 'draft. It is refused `409 RESOURCE_CONFLICT` when the active rows (or, '
-    + 'with none, the drafts) are bound to two or more packages. ⚠️ `null` is '
+    + 'with none and no package-unbound draft, the drafts) are bound to two or '
+    + 'more packages. ⚠️ `null` is '
     + 'NOT the same as absent: the implementation branches on the KEY BEING '
     + 'PRESENT, and `null` pins the lookup to the package-UNBOUND row. Spread '
     + 'it in conditionally; a present-and-`undefined` key coerces to `null` '