notes: an empty note body gets a file, and the second click writes

Reported from use: a note created with only a title then saved left a db.json
entry with no file beside it, and reopening it said the file was missing.

Cause: FileView.setText("") on a path that view has not loaded creates no
file at all and reports no error. The index write (always non-empty JSON)
was fine, so only the body was lost, which is why it looked like a missing
file rather than a failed save. Bodies are now written by a Process running
cat > <file> with the text on stdin: verified against empty and non-empty
payloads, consecutive writes on one Process, and a store with no db.json at
all. The exit code is the real outcome, so a refused write reports it.

Second report in the same flow: the editor stays editable after the first
click, so typing more and then pressing Commit & push dropped the edit, the
push carrying only what the first click wrote. The second click now writes
the current title and body before it commits and pushes.

1 files changed, 9 insertions, 6 deletions

diff --git a/desktop/modules/notes/README.md b/desktop/modules/notes/README.md
index 0f642b8..42f989f 100644
--- a/desktop/modules/notes/README.md
+++ b/desktop/modules/notes/README.md
@@ -14,9 +14,9 @@ per note, named by its creation time in epoch seconds.
   lists, links, inline code and quotes render; tables and fenced-code
   highlighting do not.
 - **Save** is two clicks: the first writes the note, the second reads
-  **Commit & push?** and pushes it. **Delete** asks first, then removes the
-  note and pushes the removal. With git off there is no second half, so Save
-  writes and returns in one.
+  **Commit & push?**, writes whatever you have typed since, and pushes it.
+  **Delete** asks first, then removes the note and pushes the removal. With git
+  off there is no second half, so Save writes and returns in one.
 - Leaving the editor with **Cancel**, the back arrow, Escape or a click
   outside drops unsaved text. The save is the explicit act.
 - **Update list** runs `git pull` and stamps `git.lastpull`.
@@ -38,9 +38,12 @@ git to resolve instead. A change made on two machines at once conflicts here
 for the same reason it conflicts for `notes.sh`: every machine appends to the
 one `db.json`.
 
-A write that fails is reported rather than assumed: the writes block, so a
-refused or failing `setText` is known when it returns, and a failed commit or
-push shows git's own message.
+A write that fails is reported rather than assumed. A body is written by a
+`Process` running `cat > <file>` with the text on stdin, not by a `FileView`:
+`setText` with an empty string, on a path that view has not loaded, creates no
+file and reports no error, which once put an empty note into `db.json` with no
+file beside it. `cat` takes any content at any length, including none, and its
+exit code is the outcome; a failed commit or push shows git's own message.
 
 **Git order.** `notes.sh` pulls before it writes and commits after, and the
 page keeps that order: creating a note pulls first, then writes on what the