Print the two shortcuts a dealer had no way to find

Seven keys drive this tool. Five of them are printed on the control they press -- F on
Fold, C on Call, R on Raise, the return arrow on Deal and on Raise to, esc on Cancel.
Two were printed on nothing at all:

  A   opens the amount pad on All-in
  U   takes back the last action

A dealer who learned F, C and R from the buttons had no way to discover the other two
existed. They are the two worth knowing: A is the fastest action in the tool and U is
the one that saves a misclick.

Both are on their controls now. The key lookup matches any of a button's classes, so
the raise pad's four quick amounts can share one class for their looks while only
All-in carries a key.

And a legend in the sidebar, listing all seven with what they do, built from the same
list the handlers are keyed off. There is a test that every key in the map has a line
in the legend and that every line names a key that really is bound -- a shortcut with
no line is one nobody can find, which is the whole bug this fixes.

The panel is hidden on a touch device. A phone has no keys to press, and it is the
same pointer question the touch-target rules ask rather than a guess about width.

One thing I broke and fixed on the way. .actionKey pins itself to the top-right corner
of a big action button. The undo control is a 30px pill with overflow hidden and no
positioning context, so the U escaped it and floated above the action bar -- visible in
the screenshot before I looked properly. It has its own inline class now, checked at
six sizes: the cap sits inside the pill and inside the bar, and the pill is not
clipped.

5 tests (249 total). Driven at six sizes across touch and pointer contexts: the undo
pill shows U, the raise pad shows A on All-in and nothing on Min, half pot and Pot, the
legend lists all seven, and it is display:none on a phone. Contrast clean, layout audit
clean but for the landscape phone already known from #63, no console errors.

Co-Authored-By: Claude Opus 5 <[email protected]>
Claude-Session: https://claude.ai/code/session_015bnp7xKUPFFSpwkYNFaPgb

JoshHeaps.Net/wwwroot/css/casino/holdem.css

@@ -1095,6 +1095,46 @@ button,
     line-height: 1.5;
 }
 
+/* The shortcut legend. A touch device has no keys to press, so it doesn't get a panel
+   telling it about them — the same pointer question the touch-target rules ask. */
+@media (pointer: coarse) {
+    #keyboardPanel {
+        display: none;
+    }
+}
+
+.shortcutLegend {
+    display: grid;
+    grid-template-columns: auto 1fr;
+    gap: 0.45rem 0.6rem;
+    margin: 0;
+    align-items: baseline;
+}
+
+.shortcutLegend dt {
+    display: flex;
+    gap: 0.2rem;
+}
+
+.shortcutLegend dd {
+    margin: 0;
+    color: #b8b8b8;
+    font-size: 0.78rem;
+    line-height: 1.35;
+}
+
+.shortcutKey {
+    background: #232323;
+    border: 1px solid #3f3f3f;
+    border-bottom-width: 2px;
+    border-radius: 4px;
+    padding: 0.05rem 0.32rem;
+    font-family: inherit;
+    font-size: 0.68rem;
+    color: #d8b46a;
+    white-space: nowrap;
+}
+
 /* One chip per ruling, wrapped across the top of the sheet. Names rather than icons:
    a dealer scanning this is looking for the words somebody at the table just said. */
 .rulingsIndex {
@@ -2117,6 +2157,20 @@ body.hasActionBar #holdemSidebar {
     font-variant-numeric: tabular-nums;
 }
 
+/* The undo pill's key, inline rather than pinned to a corner — see actionBar.js. */
+.actionUndoKey {
+    margin-left: 0.4rem;
+    padding: 0 0.25rem;
+    border-radius: 4px;
+    border: 1px solid currentColor;
+    opacity: 0.55;
+    font-family: inherit;
+    font-size: 0.6rem;
+    line-height: 1.4;
+    text-transform: uppercase;
+    pointer-events: none;
+}
+
 .actionKey {
     position: absolute;
     top: 5px;