fix: re-run dynamic prompts fed through linked text inputs

IS_CHANGED only receives constant inputs, so a linked text always
arrived as None and the node kept serving its cached first expansion.
Declare hidden PROMPT/UNIQUE_ID inputs and walk the prompt graph to
the upstream node: rerun only when its constants contain dynamic
syntax or cannot be statically resolved, keep caching for static
linked text.

Fixes #1120

py/nodes/text.py

@@ -1,6 +1,10 @@
 from __future__ import annotations
 
-from ..services.wildcard_service import contains_dynamic_syntax, get_wildcard_service
+from ..services.wildcard_service import (
+    contains_dynamic_syntax,
+    get_wildcard_service,
+    linked_text_requires_rerun,
+)
 
 
 class TextLM:
@@ -34,6 +38,10 @@ class TextLM:
                     },
                 ),
             },
+            "hidden": {
+                "prompt": "PROMPT",
+                "unique_id": "UNIQUE_ID",
+            },
         }
 
     RETURN_TYPES = ("STRING",)
@@ -42,10 +50,27 @@ class TextLM:
     FUNCTION = "process"
 
     @classmethod
-    def IS_CHANGED(cls, text: str, seed: int | None = None):
-        if contains_dynamic_syntax(text) and seed is None:
+    def IS_CHANGED(
+        cls,
+        text: str,
+        seed: int | None = None,
+        prompt: dict | None = None,
+        unique_id: str | None = None,
+    ):
+        if seed is not None:
+            return False
+        if contains_dynamic_syntax(text):
+            return float("NaN")
+        if text is None and linked_text_requires_rerun(prompt, unique_id, "text"):
             return float("NaN")
         return False
 
-    def process(self, text: str, seed: int | None = None):
+    def process(
+        self,
+        text: str,
+        seed: int | None = None,
+        prompt: dict | None = None,
+        unique_id: str | None = None,
+    ):
+        del prompt, unique_id
         return (get_wildcard_service().expand_text(text, seed=seed),)