fix(datanodes): follow the step-2 trigger chain instead of clicking once (LeyckerS#111)

datanodes now serves step 2 as two buttons: 'Free Download / Standard Speed'
reveals 'Start Download / Your file is ready', and only the second starts the
transfer. The trigger handler latched after the first click, so every free
account has been hanging for the full 420s budget and failing silently.

The page was never unreadable -- DN_STEP2_JS already matches the second button,
'start download' is the first alternative in its regex. Every poll after the
first click reported the new trigger and the latch discarded it.

Track which labels were clicked rather than whether anything was, so each new
trigger in the chain gets exactly one click. DN_STEP2_MAX_CLICKS caps it so a
page cycling labels stops instead of being clicked until the deadline.

Closes LeyckerS#109

Co-authored-by: Claude Opus 5 <noreply@anthropic.com>

Author: LeyckerS

moon_extract.py

@@ -223,6 +223,9 @@ async def extract_fuckingfast(url: str) -> str | None:
 
 DN_STEP1_GATE_TIMEOUT = 22.0
 DN_STEP2_TIMEOUT      = 420.0
+# Step 2 is a chain of buttons, not one button: each click can reveal the next.
+# The cap stops a page that cycles labels from being clicked until the deadline.
+DN_STEP2_MAX_CLICKS   = 4
 # Auto-click budget. After this the widget is left alone so a human sitting at the
 # headful window can tick it; DN_MANUAL_CAPTCHA_TIMEOUT is that grace period.
 DN_CAPTCHA_AUTO_TIMEOUT   = 45.0
@@ -724,9 +727,16 @@ def _on_popup(pop):
         if await _dn_eval(page, DN_DEAD_JS, default=False):
             return None, None
 
-        # ── step 2: Turnstile + countdown, then one click on the trigger ───────
+        # ── step 2: Turnstile + countdown, then the trigger chain ─────────────
         for hard_fail_retry in range(2):        # one reload if Turnstile hard-fails
-            clicked        = False
+            # Not a boolean. datanodes serves the trigger as a *chain*: the first
+            # button ("Free Download / Standard Speed") only reveals the second
+            # ("Start Download / Your file is ready"), and only the second starts
+            # the transfer. A one-shot latch clicked the first, then watched the
+            # second sit there for the whole 420s budget -- the page was never
+            # unreadable, we simply refused to press it. Remember which labels
+            # were used instead, so each new one gets a click and a repeat does not.
+            clicked_labels : set[str] = set()
             solved_captcha = False
             last_sweep     = 0.0
             hard_failed    = False
@@ -769,11 +779,17 @@ def _on_popup(pop):
                     solved_captcha = True
                     continue
 
-                if st["trigger"] and not clicked:
+                if st["trigger"] and st["trigger"] not in clicked_labels:
+                    if len(clicked_labels) >= DN_STEP2_MAX_CLICKS:
+                        # A page cycling labels would otherwise be clicked until the
+                        # deadline. Stop and let the caller retry from a clean page.
+                        _d(f"step-2 trigger chain exceeded {DN_STEP2_MAX_CLICKS} "
+                           f"distinct labels, last: {st['trigger']!r} — giving up")
+                        break
                     await _dn_eval(page, DN_OVERLAY_JS)
                     if await _dn_eval(page, DN_CLICK_JS, st["trigger"], default=False):
                         _d("clicked step-2 trigger:", st["trigger"])
-                        clicked = True
+                        clicked_labels.add(st["trigger"])
                 await asyncio.sleep(0.4)
 
             if not hard_failed: