notes: write and commit failures are reported, not assumed

A review of the branch found four ways the page could report success for
work that never happened, all reachable in ordinary use.

Writes: setText is asynchronous unless blockWrites, and its
saved()/saveFailed() do not fire for every write (a second setText to the
same path loses the signal, which stranded the callback), so a save was
reported before it landed and a failed db.json or body write was never
seen. Both views now block and carry the outcome, so writeDb and writeBody
know the result when they return; a failed create therefore leaves no index
entry. The create path also loads the body before the index, so a failed
body write cannot leave an entry with no text.

Commits: the sync chain swallowed every commit failure with '|| true', so a
failing pre-commit hook or a signing failure pushed an unchanged HEAD and
reported success. It now stages, commits only when something is staged, and
lets 'set -e' fail the chain, with stderr folded in for the whole chain
rather than just the push.

Duplicate notes: the 'awaiting commit' state lived only in a 3 second
timer, so a slower second click re-entered create() and appended a second
note. It is now a page property that outlives the timer, and the button
follows it.

Preview: the shared Switch writes checked itself, dropping the binding, so
the switch stopped following page.preview; resynced on change, the way
StatusRow.qml does.

Also validates a note's file name as digits before read, write or rm, and
clears the index error once the index reads again.

1 files changed, 4 insertions, 0 deletions

diff --git a/desktop/modules/notes/README.md b/desktop/modules/notes/README.md
index fa1a537..8efd7bc 100644
--- a/desktop/modules/notes/README.md
+++ b/desktop/modules/notes/README.md
@@ -37,6 +37,10 @@ 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.
+
 **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
 pull brought in, and the commit and push are the second click. The one