[ilyaZar]

Fixes #137.

During bulk pulls the folder card's activity line stayed blank or frozen because the core's event loop blocked on HTTP calls that are redundant during a pull. Details and measurements are in #137.

Changes:

• skip localIndex lookups and rescans for files ItemFinished already reported in the last 30 s; local changes are still classified and rescanned as before
• run directory rescans in a goroutine; /rest/db/scan waits for the pull and blocked the loop until the 8 s response timeout
• handle file events before the refresh in the event loop
• keep the last finished file name for 1.5 s when no other file is active, so files that start and finish within one batch still appear
• Omarchy only: keep the single folder card alive instead of letting the Repeater rebuild it on every status update; drop the now unused visibleFolderRows
• bundled binaries and checksums rebuilt

Caelestia and Dux Shell get the core fixes and needed no QML change; they do not rebuild their card.

Testing

• new TestLastFileStaysVisibleBriefly and TestLocalIndexSkipsFilesAlreadyReportedFinished; TestLocalIndexUsesCurrentFileInformation now waits for the background rescan
• go -C core test -race ./... passes
• packaging/bundled/build.sh with go1.23.12 reproduces the committed checksums
• tests/architecture.test.sh and tests/native-core-architecture.test.sh pass
• measured on a 3,348-item pull: the line shows a current file 99.3-99.7% of the time (was 5.1%), longest blank 0.3-0.7 s, name lag p90 under 0.5 s
• local changes during idle: a new file in a new directory and a deletion (Removing README.md) still show
• checked on the Omarchy panel during a real pull