docs: reconcile the backlog, close 98/100/102, drop 78 and 116

The reconciliation against the user's own notes found ZERO unrecorded
entries, the first clean pass: the 2026-08-16 sweep added items 98 to 104 and
those absorbed the whole current "Not done yet" list.

Closed this session, sections moved to the closed-items file: 98, 100, 102.

Dropped:
- 78, at the user's request. Never a defect. Items 85, 23 and 81 already give
  the whole journey (right-click a value, search it, save the query, make a
  rule from it); this was only a shortcut across it, and the entry had already
  said to gather usage evidence first. That evidence never appeared.
- 116, the same day it was raised, and its section is kept for the process
  failure rather than the non-bug. Copy image was reported as copying markup
  instead of pixels. Two explanations were eliminated by real evidence, and
  the conclusion drawn was that something more interesting must be wrong; the
  actual answer was that the measurement distinguishing them was broken. A
  wl-paste reading taken minutes after the copy showed text flavours only, was
  explicitly labelled unreliable in the entry, and was then reasoned from
  anyway. Run immediately after a copy it reports image/png and 30 more, and
  pasting into GIMP immediately works. A caveat that does not stop the
  reasoning it qualifies is decoration.

Opened:
- 112, Toggle unread on a whole thread cannot reach "all unread" on a
  partly-read thread. The direction comes from notmuch's UNION over the
  thread, so one unread message anywhere makes the action pick "mark read" and
  no input reaches the other branch. Third defect from that union after 110.
- 113, view source as our own plain-text dialog.
- 114, Save image is offered and does nothing: no downloadRequested handler
  exists anywhere. The user corrected the first proposal, which would have
  refused remote images on security grounds; once remote content is granted
  the bytes are already fetched, so saving them is a local copy and blocking
  it protects nothing.
- 115, no confirmation when a copy succeeds.
- 117, the pane offers no Select all. NOT caused by item 100: verified against
  a build with that filter reverted. Three wrong theories preceded that
  measurement, and the lesson is one item 100 had already written down: a menu
  built by hand proves nothing about the menu Chromium builds.

The changelog's Unreleased section gains Important-as-a-toggle, the rules
Note column, the menu fix, and two Upgrading notes.

1 files changed, 30 insertions, 0 deletions

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 9ca51f1..f1519a3 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -36,6 +36,18 @@ Existing `[keys]` entries keep working and keep their meaning: `delete` is still
 `flag_thread`) and can be rebound like any other. "Mark all read" is unchanged:
 it never used the selection.
 
+**Important is now a toggle.** `Ctrl+I` on something already marked important
+removes the tag, where before it re-applied it and appeared to do nothing. If
+you were using it to mark a batch that already contained important messages,
+note that a selection where *everything* is already important now unmarks all of
+it, matching how Delete and Toggle unread have always behaved.
+
+**The tagging rules window forgets its column widths once.** A Note column was
+added to the rule list, and a saved layout describing the old set of columns
+cannot be applied to the new one. The first time you open the dialog after
+upgrading, the columns are sized to fit; drag them once and the new layout is
+remembered as before.
+
 ### Changed
 
 - **Reading a message no longer marks its replies read.** The two-second
@@ -50,9 +62,27 @@ it never used the selection.
   conversation; once a thread is expanded, that row cannot say which of its
   messages are unread, and dimming alone was too quiet to notice. Replies stay
   a size smaller than their thread, so the two kinds of row still read apart.
+- **Important is a toggle**, like Delete and Toggle unread beside it. It only
+  ever added the tag, so pressing it on something already important re-applied
+  a tag that was already there, which changes nothing and looked like a dead
+  key. Removing `flagged` previously meant opening the tag dialog. As with
+  Delete, one direction is chosen for the whole selection: it unmarks only when
+  every selected row is already important, so a single keystroke cannot leave a
+  selection in two states.
+- The tagging rules window shows each rule's **Note** in the list. The field
+  explaining why a rule is shaped the way it is was only visible after
+  selecting that rule and reading the form, which is the wrong way round for
+  the one column that says what a rule is for. Long notes are elided with the
+  full text in the tooltip.
 
 ### Fixed
 
+- The message pane's right-click menu offered **Back, Forward, Reload** and
+  **Save page**. The pane is not a browser: every message is rendered from
+  memory with no history and no network, so all four were inert as well as
+  meaningless. The menu now carries only what applies to a message: Copy, View
+  source, and searching for the selected text.
+
 - Acting on a reply inside an expanded thread could read a different thread's
   state, because a reply's position is counted within its own thread and was
   being used as a position in the whole list. The first reply of any thread