[prismatic7]

Fixes #70.

Problem

Moving a folder into a watched folder left the files inside it unprocessed by automatic watching, even with the rule's scope set to All Levels. Run Now processed the same files fine.

Root cause

FSEvents only reports the folder itself when it arrives together with its contents: the files inside were created outside the watched tree, so no FileEvents entries are delivered for them. WatcherCoordinator settled the arriving folder (the whole-tree fingerprint wait already covers its contents) and then ran handle(path:) on the folder path alone — the subtree was never walked.

Fix

When a settled arrival is a directory, checkSettled now rescans its subtree via the existing handleRescanSubtree, the same path a MustScanSubDirs recovery or a deferred-descendants settle already takes. Because the arrival's includingContents snapshot only resolves once everything inside has stopped changing for a full settle interval, the entries are evaluated immediately (waitsForSettledFiles: false) — matching Run Now semantics, and giving folder moves the same mid-transfer protection file arrivals already have. The fingerprint cache keeps the rescan from re-evaluating paths whose own events also arrived, and depth limits from maxRuleDepth are respected as in Run Now.

Three-path consistency (per AGENTS.md)

• Watcher: fixed and covered by the new test.
• Dry Run / Run Now: untouched — both already walk the tree; no shared plan code changed.

Verification

• swift build clean.
• swift test: 330 tests in 28 suites, all passed (329 existing + 1 new).
• Negative test: with WatcherCoordinator.swift stashed (old code), the new test folderArrivingWithContentsProcessesThemWithoutTheirOwnEvents fails with 4 issues; with the fix, all 8 WatcherSettlingTests pass.
• Left to CI: real FSEvents delivery (the test injects the event the stream would report); no GUI run locally.