Move price badges to python nodes (#7816)

## Summary

Backend part: https://github.com/Comfy-Org/ComfyUI/pull/11582

- Move API node pricing definitions from hardcoded frontend functions to
backend-defined JSONata expressions
- Add `price_badge` field to node definition schema containing JSONata
expression and dependency declarations
- Implement async JSONata evaluation with signature-based caching for
efficient reactive updates
- Show one decimal in credit badges when meaningful (e.g., 1.5 credits
instead of 2 credits)

## Screenshots (if applicable)

<!-- Add screenshots or video recording to help explain your changes -->

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-7816-Move-price-badges-to-python-nodes-2da6d73d365081ec815ef61f7e3c65f7)
by [Unito](https://www.unito.io)

pnpm-lock.yaml

@@ -186,6 +186,9 @@ catalogs:
     jsdom:
       specifier: ^27.4.0
       version: 27.4.0
+    jsonata:
+      specifier: ^2.1.0
+      version: 2.1.0
     knip:
       specifier: ^5.75.1
       version: 5.75.1
@@ -449,6 +452,9 @@ importers:
       glob:
         specifier: ^11.0.3
         version: 11.0.3
+      jsonata:
+        specifier: 'catalog:'
+        version: 2.1.0
       jsondiffpatch:
         specifier: ^0.6.0
         version: 0.6.0
@@ -6045,6 +6051,10 @@ packages:
     engines: {node: '>=6'}
     hasBin: true
 
+  jsonata@2.1.0:
+    resolution: {integrity: sha512-OCzaRMK8HobtX8fp37uIVmL8CY1IGc/a6gLsDqz3quExFR09/U78HUzWYr7T31UEB6+Eu0/8dkVD5fFDOl9a8w==}
+    engines: {node: '>= 8'}
+
   jsonc-eslint-parser@2.4.0:
     resolution: {integrity: sha512-WYDyuc/uFcGp6YtM2H0uKmUwieOuzeE/5YocFJLnLfclZ4inf3mRn8ZVy1s7Hxji7Jxm6Ss8gqpexD/GlKoGgg==}
     engines: {node: ^12.22.0 || ^14.17.0 || >=16.0.0}
@@ -14403,6 +14413,8 @@ snapshots:
 
   json5@2.2.3: {}
 
+  jsonata@2.1.0: {}
+
   jsonc-eslint-parser@2.4.0:
     dependencies:
       acorn: 8.15.0