Add LTX audio workflow + Text (Prompt) node

New workflow/workflow_ltx_audio_api.json: Audio Wave + Segments + LoadImage (subject)
+ Text (Prompt) holding the LTX audio system prompt -> Judge in chat mode
(json_output, model 3.5-9b) -> LTX beats JSON on the analysis output. Added a tiny
CalibratorText node ('Text (Prompt)', STRING source) needed to feed the judge's
forceInput system_prompt/user_prompt/axes sockets. README points to the workflow.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

nodes/text.py

@@ -0,0 +1,27 @@
+"""
+Text (Prompt) node — a plain multiline STRING source.
+
+Needed because the judge's system_prompt / user_prompt / axes / reference_description
+are input sockets (forceInput): wire this node into them to type a value. Handy for the
+LTX system prompt, custom axes, etc.
+"""
+
+from __future__ import annotations
+
+
+class CalibratorText:
+    CATEGORY = "prompt_calibrator"
+    FUNCTION = "out"
+    RETURN_TYPES = ("STRING",)
+    RETURN_NAMES = ("text",)
+
+    @classmethod
+    def INPUT_TYPES(cls):
+        return {"required": {"text": ("STRING", {"default": "", "multiline": True})}}
+
+    def out(self, text):
+        return (text,)
+
+
+NODE_CLASS_MAPPINGS = {"CalibratorText": CalibratorText}
+NODE_DISPLAY_NAME_MAPPINGS = {"CalibratorText": "Text (Prompt)"}