feat(assets): register output files as assets after prompt execution

Add ingest_existing_file() to services/ingest.py as a public one-call
wrapper for registering on-disk files (stat, BLAKE3 hash, MIME detection,
path-based tag derivation).

After each prompt execution in the main loop, iterate
history_result['outputs'] and register files with type 'output' as
assets. Runs while the asset seeder is paused, gated behind
asset_seeder.is_disabled(). Stores prompt_id in user_metadata for
provenance tracking.

Amp-Thread-ID: https://ampcode.com/threads/T-019cc013-1444-73c8-81d6-07cae6e5e38d
Co-authored-by: Amp <amp@ampcode.com>

main.py

@@ -8,6 +8,7 @@ import time
 from comfy.cli_args import args, enables_dynamic_vram
 from app.logger import setup_logger
 from app.assets.seeder import asset_seeder
+from app.assets.services import ingest_existing_file
 import itertools
 import utils.extra_config
 from utils.mime_types import init_mime_types
@@ -229,6 +230,44 @@ def cuda_malloc_warning():
             logging.warning("\nWARNING: this card most likely does not support cuda-malloc, if you get \"CUDA error\" please run ComfyUI with: --disable-cuda-malloc\n")
 
 
+def _register_execution_outputs(history_result: dict, prompt_id: str) -> int:
+    """Register output files from a completed execution as assets."""
+    outputs = history_result.get("outputs", {})
+    if not outputs:
+        return 0
+
+    registered = 0
+    for node_id, node_output in outputs.items():
+        for key, items in node_output.items():
+            if not isinstance(items, list):
+                continue
+            for item in items:
+                if not isinstance(item, dict):
+                    continue
+                if item.get("type") != "output":
+                    continue
+                filename = item.get("filename")
+                subfolder = item.get("subfolder", "")
+                if not filename:
+                    continue
+
+                base_dir = folder_paths.get_directory_by_type("output")
+                abs_path = os.path.join(base_dir, subfolder, filename)
+                if not os.path.isfile(abs_path):
+                    continue
+
+                try:
+                    ingest_existing_file(
+                        abs_path,
+                        user_metadata={"prompt_id": prompt_id},
+                    )
+                    registered += 1
+                except Exception:
+                    logging.exception("Failed to register output: %s", abs_path)
+
+    return registered
+
+
 def prompt_worker(q, server_instance):
     current_time: float = 0.0
     cache_type = execution.CacheType.CLASSIC
@@ -264,6 +303,8 @@ def prompt_worker(q, server_instance):
             was_paused = asset_seeder.pause()
             try:
                 e.execute(item[2], prompt_id, extra_data, item[4])
+                if not asset_seeder.is_disabled():
+                    _register_execution_outputs(e.history_result, prompt_id)
             finally:
                 if was_paused:
                     asset_seeder.resume()