R15: Fix D04/D06/D07 partial completion

D04: Add fish name-based fallback in _auto_publish (was external_id only)
D06: Cap confidence at 50% for 1 player, 65% for 2 players
D07: Set caught_at=None for community imports (not published_at)
D08: Already OK - activity_rows has no top-100 limit

- Add Fish import to community_importer.py
- Add 2 unit tests for D06 confidence caps
- Update test_community_importer.py for D04 name match behavior

apps/api/app/community_importer.py

@@ -9,7 +9,7 @@ from sqlalchemy import select
 from sqlalchemy.orm import Session
 
 from .community_review import publish_observation
-from .models import DataSource, ExternalEntityAlias, ExternalObservation, ModerationStatus, Waterbody
+from .models import DataSource, ExternalEntityAlias, ExternalObservation, Fish, ModerationStatus, Waterbody
 
 
 SOURCE_DEFAULTS = {
@@ -112,12 +112,22 @@ def _auto_publish(session: Session, observation: ExternalObservation) -> bool:
         or observation.weight_g is None
     ):
         return False
-    fish_alias = session.scalar(select(ExternalEntityAlias).where(
-        ExternalEntityAlias.source_system == observation.source_system,
-        ExternalEntityAlias.entity_type == "fish",
-        ExternalEntityAlias.external_id == observation.fish_external_id,
-    ))
-    if fish_alias is None or fish_alias.fish is None:
+    # Fish: prefer external alias, fall back to exact name match
+    fish = None
+    if observation.fish_external_id is not None:
+        fish_alias = session.scalar(select(ExternalEntityAlias).where(
+            ExternalEntityAlias.source_system == observation.source_system,
+            ExternalEntityAlias.entity_type == "fish",
+            ExternalEntityAlias.external_id == observation.fish_external_id,
+        ))
+        if fish_alias and fish_alias.fish:
+            fish = fish_alias.fish
+    if fish is None:
+        # Fallback: exact name match
+        fish = session.scalar(
+            select(Fish).where(Fish.name_ru == observation.fish_name)
+        )
+    if fish is None:
         return False
     # Waterbody: prefer external alias, fall back to exact name match
     waterbody = None
@@ -136,7 +146,7 @@ def _auto_publish(session: Session, observation: ExternalObservation) -> bool:
         )
     if waterbody is None:
         return False
-    observation.fish = fish_alias.fish
+    observation.fish = fish
     observation.waterbody = waterbody
     observation.status = "ready"
     observation.review_note = "Automatically matched by previously reviewed source aliases"