Fix sync-preparing status classification

[dawez]

Problem

Syncshell classified every Syncthing folder state beginning with sync as actively syncing. Syncthing can report sync-preparing while it is preparing or processing transient remote updates, even when needTotalItems and needBytes are zero. The panel therefore flickered between preparing/syncing/scanning and up-to-date despite the folder being synchronized.

Change

Only report a folder as syncing when it has pending items or Syncthing reports the concrete syncing state. Scanning and activity handling remain unchanged.

Testing

• Added regression coverage for sync-preparing with no pending work.
• Added coverage confirming pending items still report syncing.
• Targeted QML model tests pass.
• Architecture contract test passes.
• Omarchy service contract test passes.

Root cause

The folder projection used state.indexOf("sync") === 0, which matched both syncing and the transient sync-preparing state. That prefix check was broader than the intended active-sync state.

[ilyaZar]

lgtm

thx @dawez was thinking about that too

iam doing some ui checks atm but will merge your idea once I find a good entry point in the current changes