a control for when the input state goes wrong

`POST /reset-input` and a "clicks acting wrong?" button in the panel's status
line. It releases every modifier and mouse button the display thinks is held.

Named for the SYMPTOM rather than the mechanism, because nobody experiencing
this knows a modifier is stuck — they know their clicks stopped doing the right
thing.

── both sides, and that ordering matters ──

Releasing on the server alone leaves the panel's own button mask stale and the
next mouse move re-asserts it, so the fix would appear not to work. Local state
is cleared first, a pointer event with an empty mask says so, and only then does
the server let go.

── a fixed list, not a query ──

`xinput --query-state` would report exactly what is held, which is better. It is
also a seventh host binary to declare and to require, for a repair. Releasing a
key that was not pressed is a no-op, so the fixed list costs nothing. Modifiers
and buttons only: a stuck letter types, which is obvious and harmless; a stuck
modifier silently changes what every click means.

── not guarded like the others ──

Every other command refuses while a dialog is open, because its clicks would
fall through onto the board. This one clicks nothing, and refusing a repair in
the state that most needs it would be the wrong way round.

Verified by stranding `Shift_L` on the display with `xdotool keydown`, hitting
the route, and watching `xinput --query-state` go from one key down to none.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Officer-Session: de3ed4e6-f88a-429c-94e6-a760336ba83b

sidecar/index.ts

@@ -5,6 +5,7 @@ import { VNC_SOCKET, ensureDirs } from './paths';
 import { activeDisplay, isRunning, start, status, stop } from './session';
 import { DIFFICULTIES, currentDifficulty, isDifficulty, playReplay, selectDifficulty } from './menu';
 import { isKnownReplay, listReplays } from './replays';
+import { resetInput } from './input';
 
 /*
   officer-minesweeper — owns the game session, and serves both halves of the plugin from one listener.
@@ -18,6 +19,7 @@ import { isKnownReplay, listReplays } from './replays';
     POST /difficulty  { level: beginner | intermediate | expert } — drives the game's own Game menu
     GET  /replays     ?level=<one of those> — the saved games, best first
     POST /replay      { file } — opens one, by name, and only a name /replays just returned
+    POST /reset-input releases every modifier and mouse button the display thinks is held
     GET  /ws        the display — an RFB stream, relayed frame-for-byte onto x11vnc's unix socket
 
   ─────────────────────────────────────────────────────────────────────────────────────────────────
@@ -144,6 +146,17 @@ const server = Bun.serve({
         return Response.json({ replays: listReplays(level ?? undefined) });
       }
 
+      // Deliberately NOT guarded by `blockingDialog` like the others: this is the repair for a session
+      // that is misbehaving, and refusing to run it because something is on screen would refuse it in the
+      // case it is most needed.
+      if (req.method === 'POST' && url.pathname === '/reset-input') {
+        const display = activeDisplay();
+        if (!isRunning() || !display) {
+          return Response.json({ error: 'the session is not running' }, { status: 409 });
+        }
+        return Response.json(await resetInput(display));
+      }
+
       if (req.method === 'POST' && url.pathname === '/replay') {
         const display = activeDisplay();
         if (!isRunning() || !display) {