add workaround for river wm rotation issue

src/att_lock.h

@@ -63,6 +63,20 @@ struct att_output {
 	int32_t             width, height;   /* logical size from configure */
 	bool                configured;
 	struct att_buffer   buffers[2];
+
+	/* Output geometry as last advertised by wl_output. Only ever compared
+	 * against the `cfg_*` snapshot below, never used to size a buffer: the
+	 * buffer size must come from configure alone, and with fractional scale
+	 * the integer wl_output.scale cannot reproduce the logical size anyway. */
+	int32_t  mode_w, mode_h, transform;
+
+	/* Same four values as of the most recent configure. A difference means
+	 * the output changed and the compositor has not reconfigured us. */
+	int32_t  cfg_mode_w, cfg_mode_h, cfg_transform, cfg_scale;
+
+	/* Geometry we last recreated the lock surface for, so a compositor that
+	 * ignores the recreate is nagged once rather than forever. */
+	int32_t  retry_mode_w, retry_mode_h, retry_transform, retry_scale;
 };
 
 struct att_seat {
@@ -111,6 +125,9 @@ struct att {
 	int      fail_count;     /* failed unlock attempts, pattern or password */
 	int64_t  lockout_until;  /* CLOCK_MONOTONIC ms; 0 when not locked out   */
 
+	/* CLOCK_MONOTONIC ms at which to re-examine output geometry, or 0. */
+	int64_t  resize_recheck_at;
+
 	/* configuration */
 	const char *image_path;
 	const char *pam_service;