feat(menu): dimmed keybind hints on menu rows (item 28c)

The audit flagged the root picker as six short rows in ~760px of
empty width; the space now carries discoverability. menuHint renders
a dimmed pango span (size small, 55% alpha) from the SAME keybinds.nix
the Hyprland binds and the SUPER+? cheatsheet come from (prettyKeys),
so hints can never drift. Applied to the root picker (Apps special-
cased — it's rofi drun), all Tools leaves, and the System rows with
direct binds; those menus pass -markup-rows. Contains-glob matching
and the exact "↩ Back" row are unaffected.

Verified: V0; V1 (rendered menu bash -n, spans + 3x -markup-rows
present); visual — tokyo-night 1080p capture shows the hints dimmed
and subordinate on normal and selected rows alike.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

agent/JOURNAL.md

@@ -17,6 +17,27 @@ Template:
 
 ---
 
+## 2026-07-05 — rofi keybind hints (iteration #37, item 28c)
+- **Task:** item 28 slice (c) — the hint column, the audit's biggest
+  remaining UX item.
+- **Did:** rofi.nix: menuHint builds a dimmed pango span
+  (size small, alpha 55%) from keybinds.nix via the cheatsheet's
+  prettyKeys — single source, hints can't drift from the live binds;
+  applied to root (Apps/Theme/Power/Keybindings; Apps special-cased,
+  it's rofi drun not a menu module), Tools (all eight leaves), System
+  (Network/Bluetooth/DND); those three menus now pass -markup-rows.
+  Contains-glob matching and the exact "↩ Back" match are unaffected
+  (labels keep their prefix; Back stays markup-free).
+- **Verified:** V0; V1 rendered menu bash -n + hint spans present +
+  3× -markup-rows; VISUAL — tokyo-night capture: hints render dimmed
+  and subordinate on normal AND selected (accent) rows; Tools/System
+  rows correctly bare.
+- **Pending:** slice-c remainder: summer-rasi placeholder dim,
+  latte/identity captures, icon-weight `[human]`.
+- **Next suggestion:** the placeholder-dim quickie + a latte capture
+  in one tick; then item 28 pauses for Bernardo's icon-weight call
+  and the hardware eyeballs.
+
 ## 2026-07-05 — bar group rhythm + @muted adoption (iteration #36, item 28c)
 - **Task:** item 28 slice (c) — the two queued bar polish items.
 - **Did:** waybar.nix generated CSS: margin-left 14px on the three