[PM-40747] feat: Add vault folder delete and duplicate name validation

[Ashishchidhava]

🎟️ Tracking

Local enhancement: folders on My vault had no delete action, and creating folders with the same name was allowed (e.g. two folders both named “Himalya”).

📔 Objective

Improve folder management from My vault and prevent duplicate folder names.

1. Delete / edit folder from My vault

• Folder rows on My vault now show a ⋯ more options menu.
• Options:
  • Edit → opens the existing Edit folder screen
  • Delete → confirmation dialog, then deletes the folder and shows a snackbar
• Synthetic “No Folder” rows are unchanged (no overflow menu).
• Reuses existing vaultRepository.deleteFolder and edit-folder navigation (no new delete API).

2. Duplicate folder name validation

• Creating or renaming a folder to a name that already exists is blocked (case-insensitive).
• Nested names compare the full resolved path (e.g. Parent/Child).
• Edit mode still allows saving when the name is unchanged for that same folder.
• Applied in:
  • Add/Edit folder screen (FolderAddEditViewModel)
  • Inline “add folder” from item add/edit (VaultAddEditViewModel)
• The Add folder screen subscribes to foldersStateFlow so validation uses a loaded folder list (fixes a race where .value was often empty and duplicates were allowed).
• New string: a_folder_with_this_name_already_exists → “A folder with this name already exists.”

3. Supporting UI / navigation

• BitwardenGroupItem supports an optional overflow selection list (used by vault folder rows).
• Navigation wired for NavigateToEditFolder through vault → nav bar → unlocked graph.

Tests

• FolderAddEditViewModelTest: duplicate name blocked; edit with unchanged name still saves.
• VaultViewModelTest: folder edit navigation, delete confirmation, successful delete snackbar.
• Screen/nav tests updated for the new onNavigateToEditFolderScreen callback.

📸 Screenshots

Verified on device:

• My vault folder rows show ⋯ with Edit / Delete

• Saving a duplicate folder name shows the error dialog

Test plan

• Open My vault → confirm each real folder row has a ⋯ menu
• Edit opens Edit folder and saving works
• Delete shows confirmation → folder is removed → snackbar appears
• Add folder with an existing name (same casing and different casing) → error: “A folder with this name already exists.”
• Rename a folder to another existing name → same error
• Rename a folder without changing the name → save succeeds
• Add a nested folder name that does not collide with an existing full path → save succeeds

[CLAassistant]

All committers have signed the CLA.

[bitwarden-bot]

Thank you for your contribution! We've added this to our internal tracking system for review.
ID: PM-40747
Link: https://bitwarden.atlassian.net/browse/PM-40747

Details on our contribution process can be found here: https://contributing.bitwarden.com/contributing/pull-requests/community-pr-process.

[Ashishchidhava]

Small cleanup note for reviewers: the example duplicate folder name in the description was just a local test string — happy to adjust copy or follow any Product/Engineering guidance on UX (e.g. overflow placement, delete confirmation wording).

Happy to iterate quickly on any review feedback.