feat: add menus, a toolbar and a shortcut reference

Actions were a QHash of std::function dispatched by an event filter,
which nothing could put in a menu. They are QActions now, bound from
KeyMap so a [keys] override reaches the menus as well as the keyboard.

Menu bar covers every action; the toolbar carries only Sync, Archive,
Delete and Undo. Help > Keyboard shortcuts is generated from the actions,
so it shows what the keys really do rather than a copy that drifts.
spam and load_remote gained defaults, having been unreachable without a
hand-written binding.

The event filter is gone. Probing showed QAction shortcuts are dispatched
before the focused widget sees the key, so they beat QAbstractItemView's
type-to-search without one, and Qt already suppresses plain-letter
shortcuts while an editable widget has focus. Dropping the filter's
blanket guard also lets Ctrl+Q work while the query bar has focus.

registeredActionNames() is derived from the actions rather than
hand-maintained, so the two drift tests it needed are replaced by checks
that a configured binding reaches its action.

No confirmation dialogs: tag mutations still answer to undo.

1 files changed, 32 insertions, 3 deletions

diff --git a/docs/superpowers/plans/2026-08-03-post-0.1.0-usability.md b/docs/superpowers/plans/2026-08-03-post-0.1.0-usability.md
index 8847b9b..99e26e0 100644
--- a/docs/superpowers/plans/2026-08-03-post-0.1.0-usability.md
+++ b/docs/superpowers/plans/2026-08-03-post-0.1.0-usability.md
@@ -36,13 +36,13 @@ taking that too literally.
 |---|------|---------|------|--------|
 | 1 | Splitter/column widths do not survive restart | persistence | S | open |
 | 2 | No way to see full message details (From/To/Cc/Subject) | information | M | open |
-| 3 | Too few clickable affordances, shortcuts are the only route | discoverability | M | open |
+| 3 | Too few clickable affordances, shortcuts are the only route | discoverability | M | **done** |
 | 4 | Message-pane font size does not survive restart | persistence | S | open |
 | 5 | Thread list is cramped, poor readability | presentation | S | open |
 | 6 | Opened message stays unread | behavior | S | open |
 | 7 | HTML view should be default for HTML messages | behavior | XS | **verify first, may already be done** |
-| 8 | No buttons or menu entries for archive, undo, etc | discoverability | M | open |
-| 9 | No in-app view of configured shortcuts | discoverability | S | open |
+| 8 | No buttons or menu entries for archive, undo, etc | discoverability | M | **done** |
+| 9 | No in-app view of configured shortcuts | discoverability | S | **done** |
 | 10 | Reaching an account's inbox takes two steps | workflow | S | open |
 | 11 | Icon, `.desktop` file, SlackBuild | packaging | M | open |
 
@@ -167,6 +167,35 @@ smuggle in a "Are you sure?" for Delete.
 **Verification:** the existing keymap test must still pass unchanged, proving
 user bindings survive the conversion. That is the load-bearing check here.
 
+### Outcome (done)
+
+Built as described: menu bar, toolbar, and a generated shortcut reference.
+Four things the plan did not anticipate, all verified by probe rather than
+assumed:
+
+- **The event filter was removable, but not for the stated reason.** The plan
+  worried that `QAction` shortcuts might lose to `QAbstractItemView`'s
+  type-to-search. They do not: shortcut dispatch runs before the focused
+  widget sees the key. The filter is gone, and the thread view no longer
+  needs its own.
+- **Qt already solves the query-bar case.** A plain-letter shortcut is
+  suppressed while an editable widget has focus, so the `hasFocus()` guard
+  was unnecessary. Removing it also fixed `Ctrl+Q`, which the old filter
+  swallowed while typing a query.
+- **Three default bindings had never worked.** `N`, `F` and `G` stored the
+  unshifted key, which no keystroke emits, so `toggle_unread`, `flag` and
+  `sync` were dead in 0.1.0. Fixed in `KeyMap::normalizeSequence()` and
+  committed separately from the menu work.
+- **The drift test did become unnecessary**, as the plan hoped.
+  `registeredActionNames()` is now derived from the `QAction`s, and
+  `defaultBindings()` is the single source for the defaults. The two tests
+  that pinned the hand-maintained lists together were replaced by ones that
+  check a configured binding actually reaches its action.
+
+Defaults moved to modifier shortcuts, since a single letter cannot be a menu
+accelerator without claiming that letter window-wide. Existing `[keys]`
+entries are unaffected.
+
 ## 4. Message-pane font size does not survive restart
 
 **Observed:** described as "very annoying", more so than item 1.