feat(client): show full error message on hover in analytics recent errors table

[jasnoorgill]

Summary

In the analytics Recent errors table, the message column was being
silently truncated by the existing truncate class on the <td> — operators
had no way to read the rest of the error string when a single row contained a
multi-line or long upstream error. Wrap the cell content in the existing
portal HoverTooltip so the full text is one hover (desktop) or tap-focus
(mobile) away, while the visible cell continues to clip with ... exactly
as before.

Motivation

The <td> already uses text-xs max-w-[200px] truncate, which is the
correct and desired on-screen behaviour — long error strings should not
overflow into the timestamp column. But the truncation is a one-way gate:
the operator can't recover the rest of the message from the dashboard.

Operators working on a long-tail error investigation need to see the full
error string (e.g. to distinguish a Cloudflare 600s-edge truncation from a
genuine upstream 4xx). Today they have to read the SQLite requests table
directly. A portal tooltip on the existing truncated cell closes the gap
without changing the table's layout or column proportions.

Changes

Single file, single cell, +3 / -1:

- <TableCell className="text-xs max-w-[200px] truncate">{e.error}</TableCell>
+ <TableCell className="text-xs max-w-[200px] truncate">
+   <HoverTooltip text={e.error ?? ''} side="top">{e.error}</HoverTooltip>
+ </TableCell>

• Reuses client/src/components/tooltip.tsx — the same portal Tooltip
  already imported as HoverTooltip on line 12 of AnalyticsPage.tsx and
  used elsewhere on the page (stat-card hints at line 143).
• No CSS changes. The <td>'s truncate class still does the clipping;
  the <span> rendered by HoverTooltip is the cell's only child, so the
  ellipsis still fires correctly.
• side="top" keeps the tooltip inside the visible viewport even when the
  row is in the bottom half of the max-h-[240px] scrollable container.
• Mobile gets the long-press behaviour for free: tapping the cell focuses
  the <span> (HoverTooltip already binds onFocus/onBlur), which
  triggers the same tooltip.

Why HoverTooltip and not a popover library

The project doesn't have Radix / HeadlessUI / shadcn-popover installed.
Adding one would be a ~50KB dependency for a single tooltip use-case. The
in-tree Tooltip component is already used in AnalyticsPage.tsx and
covers the requirements (hover, focus, portal positioning, viewport clamp).

Test plan

• cd client && npx tsc -b → TypeScript: No errors found
• cd client && npm run build → ✓ built in 11.18s
• Verified the tooltipped cell ships in the new bundle:
  grep -oE 'max-w-\[200px\][^"]*truncate' client/dist/assets/index-*.js
  returns the expected pattern with side:\top`andtext:e.error`.
• Manual smoke test on the running service: an analytics row with a 200+
  character error string now shows the first ~200 chars with ... and
  reveals the full string on hover (or tap-focus on mobile).

Compatibility

Client-only change, no server impact, no DB migration, no i18n string
added. Safe to backport. No public API surface change.

Notes

References operator session 2026-07-07. No upstream issue number yet —
happy to file one if requested.