docs: mention db-backup.php and simplify git update steps (#8763)

* docs: mention db-backup.php and simplify git update steps

Two follow-ups from Alkarex's review of #8741.

Backup: add ./cli/db-backup.php to the "What to back up" list as a
database-agnostic alternative to mysqldump/pg_dump. It was already
documented further down the page; the top bullet just didn't point
to it.

Updating: replace the 6-step prose list in "Using git" with a command
block matching the sequence in 07_LinuxUpdate.md. Drop the top-level
"move your backup outside the directory" warning; git reset --hard
doesn't need it, the real hazard is git clean -f -d removing
untracked files, so the warning sits inline on that line. Link to
the Linux page for the sudo and permissions-helper variant.

* docs: restore backup warning, clarify git clean note

Per @Alkarex review on #8763. Reword the inline `git clean` note to
cover untracked files generally (themes, extensions, local edits) since
backups are now called out separately above.

---------

Co-authored-by: Bjørn A. Andersen <polybjorn@users.noreply.github.com>

docs/en/admins/04_Updating.md

@@ -23,16 +23,21 @@ Log in as admin, open the Settings menu (top right), choose Administration, then
 
 ## Using git
 
-Use git to update, change branches, or switch to a specific version from the command line.
+Use git to update, change branches, or switch to a specific version. From your FreshRSS install directory:
 
 > ⚠️ Make sure your backup is outside the FreshRSS directory before starting.
 
-1. Change to your FreshRSS install directory and fetch updates.
-2. Checkout the branch or tag you wish to use (tags like `1.27.1` pin specific versions).
-3. Perform a hard reset to discard local changes.
-4. Delete files not tracked by git.
-5. Pull the new version.
-6. Re-apply file ownership and permissions.
+```sh
+git fetch --all
+git reset --hard          # discards local changes to tracked files
+git clean -f -d           # removes untracked files (custom themes, extensions, local edits)
+git checkout edge         # or `latest` for stable, or a tag like `1.27.1` for a specific version
+git pull --ff-only        # skip for a tag checkout
+```
+
+Then re-apply file ownership and permissions.
+
+See [Updating on Linux](07_LinuxUpdate.md#using-git) for the same flow with `sudo` and the FreshRSS permissions helper.
 
 ## Using a zip archive
 

docs/en/admins/05_Backup.md

@@ -5,7 +5,7 @@
 - `./data/` - **required**. You can skip `cache/` and `favicons/`; FreshRSS rebuilds them.
 - `./extensions/` - **recommended** if you use third-party extensions.
 - `./i/themes/` - **optional**, only if you have added custom themes.
-- **External database** (MySQL, MariaDB, or PostgreSQL) - back up separately with `mysqldump`/`pg_dump`. SQLite is covered by `./data/` above. See [Exporting your data](#exporting-your-data) for per-user SQLite export.
+- **External database** (MySQL, MariaDB, PostgreSQL) - back up separately with [`./cli/db-backup.php`](#creating-a-database-backup) (portable SQLite per user) or `mysqldump`/`pg_dump`. SQLite is covered by `./data/` above.
 
 All other folders belong to the source code and are restored by a fresh install or upgrade.