feat(analysis): fold non-highlighted lines in the LOG viewer

[s108105]

Summary

Adds a fold feature to the LOG Analysis viewer that collapses runs of non-highlighted lines so only highlighted content stays visible. Built as a row model on top of the existing virtualized renderer, so scrolling, bookmarks, navigation, find and the minimap stay correct.

Features

• Fold toggle in the level bar (default off, persisted). When on, consecutive non-highlighted lines collapse into a full-width fold bar shown above the next line (+ N).
• Expand / collapse: clicking a collapsed bar expands the run, showing a − 收折 collapse bar both above and below the revealed lines so it can be re-folded from either end.
• Jump arrows on expanded bars: the top bar has a down arrow (jump to the bottom of the section); the bottom bar has an up arrow (jump to the top).
• Flash hint: newly-expanded lines pulse once slowly so it's clear which section opened.
• Alt+F opens the current log directory while the analysis view is active.
• Level sync: toggling a highlight level off also folds its lines (only enabled levels count as highlighted).

Implementation

• New anaBuildRows() builds a rows model (line rows + fold-placeholder rows) with lineRow / lineDisplayRow maps so every line-index API (scroll, bookmarks, nav, find, ruler ticks) keeps working through the fold layer.
• Fold rows have an inline height equal to the measured line height to preserve fixed-height virtualization.

Testing

• npm test passes (4/4: i18n key parity, data-i18n keys exist, highlight regex valid, no duplicate IDs).
• Verified the app launches in Electron without renderer errors.