fix(pipeline): finish three changes that had only been half applied

Each of these was recorded as done and was done in one place out of two.

AR-011 -- the TransNetV2 dedup window. The derived window
(dedup_window_sec, median observed interval halved) reached scenes.json
and nothing else. SceneBoundaries, the path that actually feeds
is_scene_boundary to the tracker, kept the literal 0.04 s under a
comment claiming it "matches the dedup scenes.json applies, so the two
views agree". They did not agree. 0.04 is one frame at 25 fps and wider
than a frame at 30, so two cuts on consecutive frames merged into one
and the loss was invisible: the pipeline simply saw fewer boundaries.
The detector now supplies the window it derived.

AR-019 -- ownership. The register says ownership "comes from the
registry, not a second local tally". Both existed: promotion fired on a
local accepted-frame count and fell back to a local per-actor plurality
when the registry had not yet claimed the track. That fallback was
reachable in the live pipeline, not just in tests -- three accepted
frames arrive well before a posterior crosses the ownership threshold --
so in practice the plurality usually decided, and it could not see the
AR-025 correlation discounting it was meant to defer to. The tally is
gone; promotion now requires the registry's verdict, with the accepted
-frame count demoted to an explicit evidence floor.

AR-017 -- the route. DeadTrack carried belief but no route, and the sink
wrote the literal string "live", so a field the schema publishes could
not distinguish anything. AR-017's own verification asks for "deferred
and pooled routes distinguishable". Route is now an enum on the claim.
Only `live` occurs today; `deferred` exists so AR-020's pass has
somewhere to write instead of a serialisation change to make.

Also: TrackGallery::forget had no callers, under a comment asserting the
matcher called it "on a cut or track disappearance". The cut half was
true by another route; the disappearance half was not, so a track that
died quietly kept its diversity buffer until the next cut cleared
everything. Replaced with prune_dead against the registry's own
liveness, the same shape as the tracker's prune_boxes -- a second
opinion about which tracks exist is a second thing that can be wrong.

Removes dead logistic/logit helpers and fixes five TRACES tags that used
a comma where a pipe separates requirement types, which the gate had
been reporting as diagnostics.

TRACES: AR-011, AR-017, AR-019 | IR-002 | SR-002, SR-005

src/nodes/result_sink_node.hpp

@@ -152,6 +152,7 @@ private:
         double start{0.0};
         double end{0.0};
         float  belief{0.f};   ///< the posterior that justified the claim (AR-017)
+        Route  route{Route::live};   ///< how it was identified (AR-017)
     };
     struct ActorWindow {
         std::string name, imdb_id, tmdb_id, jellyfin_id;
@@ -180,7 +181,7 @@ private:
                     aw.jellyfin_id = it->second.jellyfin_id;
                 }
             }
-            aw.scenes.push_back({c.first_seen, c.last_seen, c.belief});
+            aw.scenes.push_back({c.first_seen, c.last_seen, c.belief, c.route});
         }
 
         std::vector<ActorWindow> result;
@@ -204,7 +205,7 @@ private:
                 windows.push_back({{"start", w.start},
                                    {"end",   w.end},
                                    {"belief", w.belief},
-                                   {"route", "live"}});
+                                   {"route", route_name(w.route)}});
             json ja;
             ja["name"]        = aw.name;
             ja["imdb_id"]     = aw.imdb_id;