feat: dynamic Frigate score threshold from stored set minimum

At the start of each person's upload phase, compute the minimum stored
Frigate recognition score across all currently mapped files. Use
max(config_threshold, dynamic_min) as the effective gate threshold so
new uploads must score at least as well as the weakest image already
in the training set.

Prevents overtraining well-recognised people: if all 80 images score
≥0.85, the dynamic threshold becomes ~0.85 and new additions that
score below that are removed rather than diluting a good training set.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

winnow/executor.py

@@ -21,6 +21,7 @@ from .quality import assess_quality
 from .upload_tracker import (
     get_frigate_filename_for_asset,
     get_lowest_quality_mapped_file,
+    get_min_frigate_score,
     get_tracked_frigate_file_count,
     get_tracked_frigate_filenames,
     has_frigate_scores,
@@ -359,6 +360,15 @@ def upload_to_frigate(jobs: list[dict]) -> None:
             effective_count = get_tracked_frigate_file_count(name)
             pre_run_count = effective_count
             quality_replacement = job.get("config", {}).get("quality_replacement", False)
+            # Dynamic threshold: at least as strict as the weakest image already stored.
+            # Takes whichever is higher — the configured floor or the current set minimum.
+            _dynamic = get_min_frigate_score(name)
+            effective_threshold = max(
+                Config.FRIGATE_SCORE_THRESHOLD,
+                _dynamic if _dynamic is not None else 0.0,
+            )
+            if _dynamic is not None and _dynamic > Config.FRIGATE_SCORE_THRESHOLD:
+                logger.debug(f"{name}: dynamic Frigate score threshold {_dynamic:.3f}")
             actually_uploaded: list[tuple[str, str | None]] = []
             failed_deletes: set[str] = set()
             quality_gate_failed: set[str] = set()
@@ -461,17 +471,16 @@ def upload_to_frigate(jobs: list[dict]) -> None:
                                 # Flag for post-reconcile removal if below threshold.
                                 # We don't know the Frigate filename yet — reconcile maps
                                 # it first, then we delete using the mapped name.
-                                threshold = Config.FRIGATE_SCORE_THRESHOLD
                                 if (
-                                    threshold > 0
+                                    effective_threshold > 0
                                     and pre_run_count > 0
                                     and post_fscore is not None
-                                    and post_fscore < threshold
+                                    and post_fscore < effective_threshold
                                 ):
                                     quality_gate_failed.add(asset_id)
                                     progress.console.print(
                                         f"    [yellow]⚠  {fname}: Frigate score {post_fscore:.2f}"
-                                        f" < threshold {threshold:.2f}, will remove after mapping[/yellow]"
+                                        f" < threshold {effective_threshold:.2f}, will remove after mapping[/yellow]"
                                     )
 
                             break
@@ -556,7 +565,7 @@ def upload_to_frigate(jobs: list[dict]) -> None:
                 if removed:
                     progress.console.print(
                         f"  [yellow]🗑  {name}: removed {removed} image(s) below"
-                        f" Frigate score threshold ({Config.FRIGATE_SCORE_THRESHOLD:.2f})[/yellow]"
+                        f" Frigate score threshold ({effective_threshold:.2f})[/yellow]"
                     )
 
             # Per-person summary

winnow/upload_tracker.py

@@ -250,6 +250,21 @@ def get_lowest_quality_mapped_file(
     return min(candidates, key=lambda x: x[2])
 
 
+def get_min_frigate_score(person_name: str) -> float | None:
+    """Return the lowest stored Frigate recognition score for this person's mapped files.
+
+    Returns None if no Frigate scores have been recorded yet (cold start or
+    feature not yet active). Used to derive a dynamic quality threshold so new
+    uploads must score at least as well as the weakest image already in the set.
+    """
+    data = _load(UPLOAD_TRACKER_FILE)
+    entry = _migrate_entry(data.get("by_person", {}).get(person_name, {}))
+    frigate_files = entry.get("frigate_files", {})
+    frigate_scores = entry.get("frigate_scores", {})
+    scored = [frigate_scores[aid] for aid in frigate_files.values() if aid in frigate_scores]
+    return min(scored) if scored else None
+
+
 def get_frigate_filename_for_asset(person_name: str, asset_id: str) -> str | None:
     """Return the Frigate training filename mapped to this asset ID, or None."""
     data = _load(UPLOAD_TRACKER_FILE)