fix(errors): let a lagging error-tick cursor cross quiet stretches in one tick - #1277

🟢 Confidence 4/5 · likely safe to merge
A fast-forwarded window relabels resolvedAt/event timestamps to the later window end (error-tick-persistence.ts:862), a disclosed tradeoff no test pins.
_{quality 100/100 · no findings · tests covered · risk medium · 3/3 new units observable}

Lets a lagging error-tick cursor cross a quiet stretch in one tick: when the claimed window is empty and the cursor is behind the cutoff, it extends the window to the next minute that has errors, or to the cutoff. The look-ahead reads the same rollup with the same predicate as the tick scan, so it cannot skip errors; safe to merge.

• errorTickNextActivityQuery returns the earliest error minute in a range
• processOrg extends an empty claimed window to the next activity minute or the cutoff
• Skips the look-ahead after a row-cap split and during bootstrap
• Tick span gains windowFastForwarded

_{84365d9 · Updated on every push. Reply "won't fix" to dismiss a finding, or mention @maple-review-bot to ask about one.}