fix: cooldown handout never truncates a longer active burn deadline

A forced soonest-recovering handout unconditionally set timeout = now + cooldown,
silently collapsing an explicit burn(proxy, 3600) to the cooldown window. Cooldown now
only EXTENDS availability delay: it leaves a still-running longer timed burn untouched
and never resurrects a permanent _DEAD (-1) burn into a future timestamp, while a fine
proxy and a burn shorter than cooldown are cooled as before.

Signed-off-by: disqualifier <dev@disqualifier.me>

src/aioproxies/manager.py

@@ -190,7 +190,17 @@ class AioProxies:
         state = self._state[proxy.key()]
         state["uses"] = int(state["uses"]) + 1
         if self.cooldown > 0:
-            state["timeout"] = int(now) + self.cooldown
+            # cooldown only ever EXTENDS availability delay - never shorten a longer
+            # active timeout (a still-running timed burn) down to now+cooldown. _DEAD
+            # (-1) is a permanent burn and must not be resurrected into a future ts.
+            cooled = int(now) + self.cooldown
+            current = state["timeout"]
+            if current == _DEAD:
+                pass
+            elif isinstance(current, (int, float)) and current > cooled:
+                pass
+            else:
+                state["timeout"] = cooled
         return proxy
 
     def _has_burned(self) -> bool: