feat: add ProjectFrameNames node — outputs stem of 3 frame paths

New node in JSON Manager/project that fetches start/middle/end frame
path from the sequence and outputs Path(value).stem for each, so
e.g. '/path/to/keyframe8.png' → 'keyframe8'. Avoids manual string
filtering in large workflows.

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

project_loader.py

@@ -383,12 +383,63 @@ class BinaryIndexDecoder:
         )
 
 
+class ProjectFrameNames:
+    """Outputs the filename stem of each frame path field (no directory, no extension).
+
+    Fetches start frame path, middle frame path, and end frame path from the
+    sequence data and returns Path(value).stem for each, so you get e.g.
+    'keyframe8' instead of '/some/dir/keyframe8.png'.
+    """
+
+    @classmethod
+    def INPUT_TYPES(s):
+        return {
+            "required": {
+                "source_label": ("STRING", {"default": "", "multiline": False}),
+            },
+            "optional": {
+                "manager_url": ("STRING", {"default": "http://localhost:8080", "multiline": False}),
+                "project_name": ("STRING", {"default": "", "multiline": False}),
+                "file_name": ("STRING", {"default": "", "multiline": False}),
+                "sequence_number": ("INT", {"default": 1, "min": 1, "max": 9999}),
+            },
+        }
+
+    RETURN_TYPES = ("STRING", "STRING", "STRING")
+    RETURN_NAMES = ("start_name", "middle_name", "end_name")
+    FUNCTION = "fetch_frame_names"
+    CATEGORY = "JSON Manager/project"
+    OUTPUT_NODE = False
+
+    @classmethod
+    def IS_CHANGED(cls, **kwargs):
+        return float("nan")
+
+    def fetch_frame_names(self, source_label, manager_url="http://localhost:8080",
+                          project_name="", file_name="", sequence_number=1):
+        sequence_number = int(sequence_number)
+        data = _fetch_data(manager_url, project_name, file_name, sequence_number)
+        if data.get("error") in ("http_error", "network_error", "parse_error"):
+            logger.warning("ProjectFrameNames.fetch_frame_names failed: %s", data.get("message"))
+            return ("", "", "")
+
+        def stem(path_str):
+            return Path(path_str).stem if path_str else ""
+
+        return (
+            stem(data.get("start frame path", "")),
+            stem(data.get("middle frame path", "")),
+            stem(data.get("end frame path", "")),
+        )
+
+
 # --- Mappings ---
 PROJECT_NODE_CLASS_MAPPINGS = {
     "ProjectLoaderDynamic": ProjectLoaderDynamic,
     "ProjectSource": ProjectSource,
     "ProjectKey": ProjectKey,
     "ProjectResolution": ProjectResolution,
+    "ProjectFrameNames": ProjectFrameNames,
     "BinaryIndexDecoder": BinaryIndexDecoder,
 }
 
@@ -397,5 +448,6 @@ PROJECT_NODE_DISPLAY_NAME_MAPPINGS = {
     "ProjectSource": "Project Source",
     "ProjectKey": "Project Key",
     "ProjectResolution": "Project Resolution",
+    "ProjectFrameNames": "Project Frame Names",
     "BinaryIndexDecoder": "Binary Index Decoder",
 }