fix: resolve application log filenames against their directory

[jkmassel]

Fixes a bug where ApplicationLogDataProvider.readFiles(in:) throws on the first entry in any non-empty directory.

Found while sweeping for the URL.path() shape from #26005. Unrelated to that bug, so it's on its own.

Summary

• contentsOfDirectory(atPath:) returns bare filenames, not paths.
• Those names went straight to ApplicationLog(filePath:), which calls attributesOfItem(atPath:) — so the lookup resolved against the process's working directory rather than the directory that was passed in, and threw.
• Latent. No shipping conformer calls this default implementation; WpLogDataProvider gets its logs from CocoaLumberjack's sortedLogFileInfos, which are already full paths.

Root Cause

Modules/Sources/Support/SupportDataProvider.swift

try FileManager.default.contentsOfDirectory(atPath: directory.path).compactMap { filePath in
    try ApplicationLog(filePath: filePath)
}

The closure parameter is named filePath, but contentsOfDirectory(atPath:) documents its return as "the names of the items" — a.log, not /…/logs/a.log. ApplicationLog(filePath:) is init? and throwing, and the missing-file case is the throwing one, so this doesn't degrade to an empty result — it propagates out of the compactMap and fails the whole call.

Fix

Resolve each name against directory before handing it to ApplicationLog, and rename the closure parameter to filename so the next reader isn't told it's a path.

Test plan

• Added ApplicationLogDataProviderTests — five cases: reads every log in a directory, resolves each path against that directory, handles a filename with a space, round-trips the contents through the default readApplicationLog, and returns nothing for an empty directory.
• Verified the tests fail without the fix.
• WordPressTest/ApplicationLogDataProviderTests — 5/5 pass on an iOS 26.4 simulator.

The Support module has no test target of its own, so the tests live in KeystoneTests, which already imports it. Adding a target for one default implementation looked disproportionate; happy to add one if you'd rather.

[wpmobilebot]

📲 You can test the changes from this Pull Request in Jetpack by scanning the QR code below to install the corresponding build.

	App Name	Jetpack
	Configuration	Release-Alpha
	Build Number	34434
	Version	PR #26010
	Bundle ID	com.jetpack.alpha
	Commit	007e265
	Installation URL	0u9hdo1go8mq8

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[wpmobilebot]

📲 You can test the changes from this Pull Request in WordPress by scanning the QR code below to install the corresponding build.

	App Name	WordPress
	Configuration	Release-Alpha
	Build Number	34434
	Version	PR #26010
	Bundle ID	org.wordpress.alpha
	Commit	007e265
	Installation URL	30sq96o00fo80

Automatticians: You can use our internal self-serve MC tool to give yourself access to those builds if needed.