feat(android): one backup destination, a group the account owns alone

Chosen once at the top of Android Sync for every kind; photos and contacts
go into <folder>/<account>-photos and -contacts. Owner and sole member are
checked at set-up and before every run.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

1 files changed, 35 insertions, 32 deletions

diff --git a/docs/USERGUIDE.md b/docs/USERGUIDE.md
index d8e793f..4c5c61e 100644
--- a/docs/USERGUIDE.md
+++ b/docs/USERGUIDE.md
@@ -382,55 +382,58 @@ coordinates are still inside the photo itself, as your phone wrote them, so
 anyone who downloads the original file has them. Strip them before sharing if
 that matters to you.
 
-### Backing up your phone's photos
+### Backing up your phone
 
-On the Android application, **Phone → Android Sync** in the side menu holds
-**Photo backup**, which sends the photos taken on your phone to a folder of one
-of your groups, once a day.
+On the Android application, **Phone → Android Sync** in the side menu backs up
+your phone's photos and contacts to a group.
 
-- **Set up** asks for access to your photos, then for a group, a folder and the
-  albums to send. Only folders you may add to and that the group's Photos tab
-  shows are offered. The camera is ticked; screenshots and other albums are
-  yours to add.
+**Where backups go** is chosen once, at the top of the page, for every kind:
+
+- **Only a group you own and are the only member of** can receive them: your
+  photos and your address book are not the group's. If you have none, create a
+  group just for yourself first. If somebody joins it or is invited later,
+  every backup stops and tells you.
+- You choose any folder of that group you may add to. Each kind of backup gets
+  a folder named after you inside it: `Backups/alice-photos`,
+  `Backups/alice-contacts`. The page tells you if the group's Photos tab does
+  not show the photos folder; add it in the group settings to see them there.
+- Choosing another group or folder later starts every backup again in the new
+  place. What was already sent stays where it is.
+
+#### Photos
+
+- **Set up** asks for access to your photos, then for the albums to send. The
+  camera is ticked; screenshots and other albums are yours to add.
 - By default **the photos already on the phone are sent too**, newest first,
   then each new one. Choose "Only photos taken from now on" to skip the ones
-  already there.
-- Before anything is sent you are told where the photos go, how many members
-  the group has and how much will be sent. **Everyone in that group will be
-  able to see and download them.** You can delete what you sent afterwards,
-  but not the copies others have already downloaded — so pick the group with
-  care. Changing the group or the folder later asks again.
+  already there. Before the first send you are told how many photos and how
+  much that is.
 - It runs **on Wi-Fi only** (more exactly, on a connection that is not charged
-  by the amount), once a day, while the application is open — with the screen
+  by the amount), once a day, while the application is open, with the screen
   off too. If the application was not opened all day, it runs the next time it
   is. **Back up now** runs at once; on mobile data it tells you how much it is
   about to send and asks first.
-- Photos go into folders by year, then year and month (`2026/2026-10`). **A photo you delete
-  from the phone stays in the group**, and one deleted from the group is not
-  sent again, unless the application is reinstalled. A photo you edit on the phone is sent again beside the original,
-  with `-edited-` and the date in its name.
+- Photos go into folders by year, then year and month (`2026/2026-10`). **A
+  photo you delete from the phone stays in the group**, and one deleted from
+  the group is not sent again, unless the application is reinstalled. A photo
+  you edit on the phone is sent again beside the original, with `-edited-` and
+  the date in its name.
 - **Where a photo was taken is removed** from the copy that is sent.
-- If the backup cannot go on — the node's disk is full, the folder no longer
-  accepts files, you left the group — it stops, says why once in a
-  notification and on the Android Sync page, and tries again the next day.
 
-### Backing up your phone's contacts
+#### Contacts
 
-**Contacts backup**, on the same **Android Sync** page, sends a copy of your
-phone's contacts to a group, once a day when they have changed.
-
-- **Only a group you are the only member of** can receive it: your address
-  book is not something to share. If you have none, create a group just for
-  yourself first. If somebody joins that group later, the backup stops and
-  tells you.
-- You choose any folder of that group you may add to; the copies go into a
-  folder named after you inside it, such as `Backups/alice-contacts`.
+- **Turn on** asks for access to your contacts, then sends a copy once a day
+  when they have changed.
 - Each copy is a `.vcf` file with the date in its name
   (`contacts-2026-10-10-0900.vcf`). Any phone can import it. Older copies are
   kept, nothing is ever replaced.
 - It runs on any connection, since a copy is small. **Back up now** sends one
   at once if your contacts changed since the last copy.
 
+If a backup cannot go on (the node's disk is full, the folder no longer accepts
+files, somebody else joined the group), it stops, says why once in a
+notification and on the Android Sync page, and tries again the next day.
+
 ### Search
 
 The magnifying glass in the sidebar searches **across every group you are in**