feat(mindspace): add page quota grace write and local delivery guardrails.

Centralize page HTML quota checks with grace-write semantics across page
services and workspace tools, keep localhost MindSpace links clickable in
chat display, and expand Page Data/static-page skill plus local dev docs
for quota, delivery URLs, and native Aider/OpenHands tooling.

Co-authored-by: Cursor <cursoragent@cursor.com>

mindspace-pages.mjs

@@ -22,6 +22,7 @@ import { prepareHtmlPageBrandMarkers } from './mindspace-page-tag.mjs';
 import { purgeWorkspacePageArtifacts, extractAssetIdsFromHtml } from './mindspace-page-purge.mjs';
 import { ensureWorkspaceHtmlThumbnail, workspaceThumbnailRelativePath } from './mindspace-workspace-thumbnails.mjs';
 import { upsertMindspaceCoverMeta } from './mindspace-cover-meta.mjs';
+import { assertPageWriteQuota } from './mindspace-space-quota.mjs';
 
 const MAX_TITLE_LENGTH = 255;
 const MAX_SUMMARY_LENGTH = 1000;
@@ -393,13 +394,10 @@ export function createPageService(pool, options = {}) {
       if (!space || space.status !== 'active') {
         throw pageError('用户空间不可用', 'space_unavailable');
       }
-      const available =
-        asNumber(space.quota_bytes) - asNumber(space.used_bytes) - asNumber(space.reserved_bytes);
-      if (available < normalized.contentBytes) {
-        throw pageError('剩余空间不足', 'quota_exceeded', {
-          requiredBytes: normalized.contentBytes,
-          availableBytes: Math.max(0, available),
-        });
+      try {
+        assertPageWriteQuota(space, normalized.contentBytes);
+      } catch (error) {
+        throw pageError(error.message, error.code ?? 'quota_exceeded', error.details);
       }
       const [categories] = await conn.query(
         `SELECT id, category_code FROM h5_space_categories