feat: use real system defaults scanner to populate items on the filesystem untracked tab

[Scott McMaster (scottmcmaster)]

Summary

Leverage the existing "system defaults scanner" functionality to populate the untracked "defaults" item on the filesystem untracked tab. For now it uses prompt seeding to complete the tracking; I will follow up with another change to do the direct-edits.

I also moved the "defaults" section to the top since it will pop in faster than Homebrew info.

Test Plan

This one is primarily a manual thing.

• No test plan needed

Docs

• Docs updated (companion PR in darkmatter/nixmac-web: #___)
• No docs update needed

[Scott McMaster (scottmcmaster)]

Warning

This pull request is not mergeable via GitHub because a downstack PR is open. Once all requirements are satisfied, merge this PR as a stack on Graphite.
Learn more

• feat: direct system-defaults apply path, fix found issues in the existing system-defaults defs #406
• feat: use real system defaults scanner to populate items on the filesystem untracked tab #404 👈 (View in Graphite)
• feat: use real homebrew untracked diff in filesystem view #403
• feat: add homebrew_add_casks managed-edit command and wire up direct tracking in the filesystem UI #393
• develop

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[github-actions]

	Warnings
⚠️	New TypeScript source files were added without any new tests: apps/native/src/hooks/use-system-defaults-scan.ts

📋 PR Overview

Lines changed	513 (+428 / -85)
Files	1 added, 15 modified, 0 deleted
Draft / WIP	no
Has Test Plan	yes
No Test Plan Needed	no
New UI components	no
New Storybook stories	no
New Rust modules	no
New TS source files	yes (1)
New tests	no
package.json touched	no
Cargo.toml touched	no
Infra / CI touched	no

🔬 Coverage

Report	Lines	Statements	Functions	Branches
apps/native/coverage/coverage-summary.json	26.0%	26.1%	25.1%	18.9%

Generated by 🚫 dangerJS against ee594f2

[Copilot]

Pull request overview

This PR wires the existing Rust “system defaults scanner” into the native app’s Filesystem → Untracked (“manage”) surface, so the “Custom macOS defaults” candidate is populated from real scan results (and reordered to appear earlier).

Changes:

• Added a frontend hook to invoke scan_system_defaults and plumb results into BeginStep + FilesystemStep.
• Reworked Filesystem “Custom macOS defaults” candidate generation to be data-driven from SystemDefaultsScan (including new CandidateItem source metadata).
• Updated stories, snapshots, and unit tests to reflect the new system-defaults candidate behavior.

Reviewed changes

Copilot reviewed 15 out of 16 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
apps/native/src/hooks/use-system-defaults-scan.ts	New React hook to call tauriAPI.scanner.scanDefaults() and expose {scan, error}.
apps/native/src/components/widget/steps/begin-step.tsx	Uses system-defaults scan to populate BeginStep’s untracked banner candidates.
apps/native/src/components/widget/filesystem/filesystem-step.tsx	Integrates system-defaults scan output into the Untracked/manage file list; tightens Homebrew tracking item typing.
apps/native/src/components/widget/filesystem/data.ts	Adds system-defaults candidate mapping + placeholder replacement; refactors CandidateItem into a discriminated union with source.
apps/native/src/components/widget/filesystem/data.test.ts	Adds unit coverage for system-defaults scan → FsFile mapping and placeholder replacement.
apps/native/src/components/widget/filesystem/untracked-card.stories.tsx	Updates story fixture to use systemDefaultsFileFromScan.
apps/native/src/components/widget/filesystem/untracked-banner.stories.tsx	Updates banner fixture to include system-defaults placeholder replacement.
apps/native/src/components/widget/filesystem/seed-prompt.stories.tsx	Updates seed prompt fixtures so defaults content comes from scan-based file generation.
apps/native/src/components/widget/filesystem/file-list.stories.tsx	Updates fixture manage files list to include scan-based defaults candidate.
apps/native/src/components/widget/filesystem/snapshots/untracked-card.stories.tsx.snap	Snapshot updates for scan-based defaults candidate rendering.
apps/native/src/components/widget/filesystem/snapshots/untracked-banner.stories.tsx.snap	Snapshot updates for new candidate counts/ordering.
apps/native/src/components/widget/filesystem/snapshots/seed-prompt.stories.tsx.snap	Snapshot updates for seed text ordering/content.
apps/native/src/components/widget/filesystem/snapshots/section-tabs.stories.tsx.snap	Snapshot updates for revised “Untracked” count.
apps/native/src/components/widget/filesystem/snapshots/file-list.stories.tsx.snap	Snapshot updates for manage list ordering/content.
apps/native/src-tauri/src/system/scanner.rs	Adds a manual debug scan helper in the test module.

[graphite-app]

Merge activity

• Jun 12, 11:54 PM UTC: czxtm added this pull request to the Graphite merge queue.
• Jun 12, 11:55 PM UTC: CI is running for this pull request on a draft pull request (#408) due to your merge queue CI optimization settings.
• Jun 12, 11:58 PM UTC: The Graphite merge queue removed this pull request due to downstack failures on PR #393.
• Jun 12, 11:58 PM UTC: The Graphite merge queue removed this pull request due to downstack failures on PR #393.