docs(backlog): record item 44 as done

The tagging rules moved from the shell post-new hook to a shared JSON
store both qtmaildir and mailctl read. Seventeen real rules were
converted, each keeping its shell comment as a note, and the conversion
was proved against the real index before anything was installed.

Four findings are recorded in CLAUDE.md rather than only here, because
they will outlive the item: a stored query carries no scope and the hook
parenthesises it (a disjunction would otherwise escape tag:new and match
everything); notmuch's parser rejects almost nothing, so a test asserting
a provoked query failure fails against correct code; rule counts must
count messages rather than threads; and a count request must not bump the
query generation, which would blank the message pane.

1 files changed, 34 insertions, 0 deletions

diff --git a/CHANGELOG.md b/CHANGELOG.md
index a555fb4..846e5c6 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -13,6 +13,15 @@ point at which they are stable.
 
 ### Added
 
+- The rules that tag your mail as it arrives are now visible and editable from
+  Message > Tagging rules, and each one shows how much mail it matches so you
+  can judge a rule before the next sync applies it. They live in a shared file,
+  `~/.config/mailrules/rules.json`, which the notmuch `post-new` hook reads to
+  do the tagging and which the companion `mailctl` tool can read too. The rules
+  previously lived inside the hook as shell, where nothing but a text editor
+  could see them. Each rule keeps a note, so the reasoning behind it (which
+  senders it deliberately excludes, and why) travels with the rule instead of
+  being a comment only one program could read.
 - A tag change now syncs itself out, about two seconds after you stop making
   changes, instead of waiting for the Sync button or your cron job. The delay is
   a debounce, so tagging several threads in a row produces one sync rather than
@@ -37,6 +46,31 @@ point at which they are stable.
   message you are reading in Unread gets marked read, the pane keeps showing it
   and offers "Show it anyway" instead of going blank.
 
+### Upgrading
+
+The tagging rules moved out of the notmuch `post-new` hook and into
+`~/.config/mailrules/rules.json`. The dialog reads and writes that file, but
+nothing applies the rules until the new hook is installed, so this needs two
+files copied from the companion `mailctl` project into your notmuch hooks
+directory:
+
+```bash
+DB="$(notmuch config get database.path)"
+cp post-new mailrules.py "$DB/.notmuch/hooks/"
+chmod +x "$DB/.notmuch/hooks/post-new"
+```
+
+Keep a backup of your previous hook until a sync has run with the new one. Your
+existing rules do not convert themselves: each `notmuch tag` line becomes one
+entry in the JSON file, with the part after `tag:new and` as its query. Leave
+`tag:new` out of the stored query, the hook adds it, and do not carry over the
+final `notmuch tag -new` line, which the hook now does itself.
+
+Two behaviours of the new hook are worth knowing. It refuses to remove `unread`
+or `inbox`, since neither belongs in an unattended job that runs every ten
+minutes, and it will not consume the `tag:new` marker if the rules file fails
+to load, so a broken file delays tagging rather than losing it.
+
 ## [0.15.0] - 2026-08-11
 
 Sent mail becomes a place you can go. A Sent button beside Inbox, Unread and