fix(filter_protocol): route live FilterTransform instances via static catalogue

thunkCreate inserted the just-minted shared_ptr<FilterTransform> into a
per-instance live_instances_ map, but thunkDeleteInstance (a free
function — the per-id deleter handed back to plugins cannot capture
context) erased from the static catalogue() that nothing inserted
into. Net effect: every transform instance leaked forever, and the
library_owner shared_ptr ref that pins the plugin DSO never dropped
— a dialog refresh (which creates one instance per registered builtin,
12 of them) was an unbounded leak.

Route both insert and delete through catalogue() so the lifecycle is
consistent. Drop the dead live_instances_ member.

Author: pabloinigoblasco

pj_plugins/include/pj_plugins/host/filter_registry_host.hpp

@@ -157,11 +157,16 @@ class FilterRegistryHost {
     }
     // The cross-DSO contract owns the raw pointer by handle. Stash the
     // shared_ptr so its deleter (which carries library_owner) survives until
-    // the caller releases the handle via the per-id deleter.
+    // the caller releases the handle via the per-id deleter. Must route via
+    // catalogue() — the static map that thunkDeleteInstance erases from —
+    // because the per-id deleter handed back by thunkLookupDeleter is a free
+    // function and cannot capture `self`. An earlier draft of this file
+    // populated a per-instance map (self.live_instances_) that thunkDelete
+    // never erased from, leaking every instance forever.
     auto* raw = sp.get();
     {
       std::lock_guard<std::mutex> lock(self.mutex_);
-      self.live_instances_.emplace(raw, std::move(sp));
+      catalogue().emplace(raw, std::move(sp));
     }
     return reinterpret_cast<PJ_filter_transform_t*>(raw);
   }
@@ -227,11 +232,10 @@ class FilterRegistryHost {
   std::mutex mutex_;
   LibraryOwnerResolver resolver_;
   std::vector<std::string> cached_id_views_;
-  // Bridges from raw FilterTransform* (what crosses the C ABI) back to the
-  // shared_ptr<FilterTransform> the factory minted (its deleter carries the
-  // library_owner). When the plugin frees the handle, we drop the shared_ptr
-  // — that runs the deleter and the DSO ref drops.
-  std::unordered_map<sdk::FilterTransform*, std::shared_ptr<sdk::FilterTransform>> live_instances_;
+  // Live-instance bridge from raw FilterTransform* to the shared_ptr the
+  // factory minted is stored in the static catalogue() above, not here — the
+  // per-id deleter handed back by thunkLookupDeleter is a free function and
+  // can only reach the static.
 };
 
 }  // namespace PJ