Add frame-aware locate for cross-origin iframe steps

Selectors were only resolved against the top document, so steps targeting
the Lucid WooCommerce checkout (rendered in a lucidtrading.com iframe under
the dash.lucidtrading.com app) never matched — e.g. input#coupon_code_field.

Add an optional `frame` on click/type/waitFor naming the <iframe> element.
The extension measures the iframe in the top frame (pageFrameOffset), finds
the element across child frames (pageLocate `relative` mode), and composes
the two into desktop coordinates; the Python side is unchanged since the
result keeps the same shape. Without `frame`, every path behaves as before.

Point the Lucid checkout steps at the frame and harden the coupon selectors
(the exact field id is still unconfirmed against the live iframe).

Extension 0.13.0, runner 0.19.0.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

clicker/runner.py

@@ -34,7 +34,7 @@ HEARTBEAT_SECONDS = 2.0
 # Bumped whenever the step vocabulary or the locate protocol changes. Reported in
 # the heartbeat so the dashboard can say "restart your runner" instead of letting
 # a stale process fail on a step type it has never heard of.
-VERSION = "0.18.0"
+VERSION = "0.19.0"
 
 # Shared with the heartbeat thread: whether a run is currently executing.
 _busy = threading.Event()
@@ -97,11 +97,19 @@ def run_one_step(dash: Dashboard, step: dict, opts, rng, report, run_id: int | N
             if run_id is not None and run_status(dash, run_id) == "cancelled":
                 raise actions.StepError("cancelled while waiting")
 
+            # A frame-scoped gate resolves the selector inside the named <iframe>;
+            # `hidden` adds the visibility probe. Either can be set independently.
+            loc_opts: dict = {}
+            if by_sight:
+                loc_opts["op"] = "visible"
+            if step.get("frame"):
+                loc_opts["frame"] = step["frame"]
+
             try:
                 seen = dash.locate(selector, int(step.get("index", 0)),
                                    step.get("urlPattern", "") or opts.url,
                                    opts.timeout, step.get("openUrl", "") or "",
-                                   options={"op": "visible"} if by_sight else None)
+                                   options=loc_opts or None)
                 if by_sight:
                     # An extension too old for the probe quietly does an ordinary
                     # locate instead, whose result has no `visible` key — reading
@@ -190,6 +198,7 @@ def run_one_step(dash: Dashboard, step: dict, opts, rng, report, run_id: int | N
                 url=step.get("urlPattern", "") or opts.url,
                 open_url=step.get("openUrl", "") or "",
                 signed_out=step.get("signedOut", "") or "",
+                frame=step.get("frame", "") or "",
                 text=step.get("text"),
                 clear=bool(step.get("clear")),
                 scale=opts.scale,