refactor(lists): remove the List Folders feature, keep parent/child list nesting

[Adron]

Summary

Removes the List Folders feature — the vertical slice that let lists be grouped into folders — in its entirety, from the sidebar UI down through the domain service and the Kit endpoint/DTO.

Parent/child list nesting is unaffected and stays. The two were independent concepts that merely both happened to nest: the Lists sidebar continues to render the owned-lists tree via OwnedList.parentID under Section("Lists"). The Documents "folder" feature (FolderNode / FolderRecord / FolderTreeViewModel) is a different feature and is untouched.

What changed

Deleted (8 source files + their tests):

Layer	Removed
App	ListFoldersSectionView, ListFoldersViewModel
Domain	ListFolder model, ListFoldersService
Kit	ListFoldersEndpoint, ListFolderDTO
Tests	ListFoldersViewModelTests, StubListFoldersService, ListFoldersServiceTests, ListFoldersEndpointTests

Rewiring:

• OwnedListsRootView — drop ListFoldersSectionView() from the sidebar List.
• AppEnvironment — drop the listFolders service, the retained listFoldersAPI, its init parameter/assignment, the live() wiring, and the associated doc comments.
• Repoint two comments that referenced the deleted symbols (ShareLinksViewModel, the AppEnvironment sharing doc).

Docs: work-consolidation.md still listed "List Folders (cycle-safe tree)" under already-shipped Collaboration features; that snapshot is now stale, so the claim is retired with a note on the removal and date.

Net: 13 files changed, 4 insertions, 1262 deletions.

Verification — full E2E gate observed green

Every leg was run and observed on 2026-09-05:

Gate leg	Result
xcodebuild -scheme InterlinedList -destination 'platform=macOS' build	** BUILD SUCCEEDED **
App target test (CODE_SIGNING_ALLOWED=NO)	622/622 pass, 0 failures
swift test — InterlinedKit	314/314
swift test — InterlinedDomain	619/619
swift test — InterlinedPersistence	135/135
Decision 0003 — ^\s*import InterlinedKit in App/Features|Navigation|MenuCommands	0 hits
git grep -l ListFolder	0 tracked hits

Note: commit 1afb89d's message states the App-target gate could not be run — at authoring time the machine's shell could not resolve uid 501, so xcodebuild aborted pre-compilation. That environment fault is resolved and the App build + test gate has since been run green, as recorded above. The commit message is left as-authored; this table supersedes it.

Two small gotchas worth knowing for future review of this area:

• A plain grep -rn "import InterlinedKit" over the feature dirs returns 4 hits, but all four are comment text literally saying "does not import InterlinedKit". Anchor the pattern to the line start for the true count.
• grep -rn ListFolder across the repo hits Packages/*/.build/ artifacts only; git grep over tracked files is clean.

Risk

Low. Pure deletion with no behavioral substitute needed — no dangling references remain, and the retained parent/child nesting path is covered by the existing owned-lists tests.

🤖 Generated with Claude Code

https://claude.ai/code/session_013tAJgfBGnnA1HgRGAWvkRK