fix: review fixes 01-1.1, 1.2, 03-3.1, 3.2, 3.3, 3.4, 3.9

[daggerok]

Review fixes from the 2026-10-11 code review (plans 01 and 03), applied with patch-brands-critical.py and patch-brands-perf.py; every anchor matched exactly once

Commits

1. fix: 01-1.1+1.2+03-3.2 critical fixes
   • 01-1.1 holdings count as loaded only when every page loaded: a failed load is marked failed (no endless "Loading…"), deselect + reselect retries it, a load cancelled by deselecting resumes on the next selection
   • 01-1.2 fetchJson aborts after 30 s (headers and body)
   • 03-3.2 sheet pages are appended in place instead of concat copies (the tableView cache still invalidates: its signature carries the row count)
2. perf: 03 sheet window, sort keys, delegation, incremental sheetView
   • 03-3.1 Holdings and History mount 300-row chunks that grow on scroll or click; filters, sort, exports still use every loaded row
   • 03-3.3 sort keys are computed once per row (same order as before: numbers, then 21-Aug-2026 dates, then numeric collation; empty values last)
   • 03-3.4 one delegated listener per event on the table body; Watchlist appends the next chunk instead of re-rendering everything
   • 03-3.9 sheet row objects are built once and reused while pages arrive

Checks run

• bun install --frozen-lockfile, bun test, bun build --target=bun src/main.tsx --outfile=/dev/null, bun run build, git diff --check
• .claude/tools/etfs/tc/check.sh: no type errors
• browser (ui-std, built site): brand filters test, columns-uitest.ts, categories-uitest.ts: all 0 failed; console errors: none
• Playwright check of the changed paths: select 3 funds through the delegated checkbox listener, Watchlist renders and grows on click with consecutive row numbers, fund link opens its Overview, Holdings of the largest fund mounts at most 2 chunks first and reaches every row by scrolling, sorting resets the window, unselect works; no console errors

Manual checks still worth doing

• on the live site: a fund with thousands of holdings scrolls smoothly; Watchlist of 3+ large funds

WisdomTree results: 44pass unit tests; brand-uitest, columns-uitest, categories-uitest 0 failed; Playwright check 16 passed, 0 failed (UNIY AGGY DDWM, 6159 holdings rows)