Clarify built-in CSSX caching docs

Author: cray0000

packages/babel-plugin-rn-stylename-to-style/README.md

@@ -131,8 +131,9 @@ so these files shouldn't frequently change.
 
 **Default:** `undefined`
 
-Whether to use integration with some caching library. Currently supported ones:
-- `"teamplay"`
+Legacy compatibility option. `"teamplay"` is still accepted for older configs,
+but style caching is owned by CSSX internally and does not require Teamplay or
+`observer()`.
 
 #### `platform`
 

packages/babel-plugin-rn-stylename-to-style/index.js

@@ -140,9 +140,9 @@ module.exports = function (babel) {
     const partStyle = styleHash[ROOT_STYLE_PROP_NAME]?.partStyle
     const inlineStyles = []
 
-    // Always process if 'observer' import is found in the file
-    // which is needed for styles caching.
-    // Otherwise, if no 'observer' found and no 'styleName' or 'part' found then skip
+    // Keep old observer-triggered behavior for files that relied on cached
+    // inline style prop normalization without styleName/part attributes.
+    // Normal styleName handling does not require observer().
     if (!(hasObserver || styleName || partStyle)) return
 
     // Check if styleName exists and if it can be processed
@@ -521,7 +521,8 @@ function buildDynamicPart (expr, part) {
   }
 }
 
-// if cache is 'teamplay'
+// Legacy cache compatibility: observer imports still select the old
+// cssxjs/runtime/*-teamplay entrypoints, which now wrap the unified runtime.
 function checkObserverImport ($import, state) {
   const observerImports = state.opts.observerImports || DEFAULT_OBSERVER_IMPORTS
   const observerName = state.opts.observerName || DEFAULT_OBSERVER_NAME
@@ -587,8 +588,8 @@ function getRuntimePath ($node, state, hasObserver) {
       `Invalid cache option value: "${cache}". Supported values: ${OPTIONS_CACHE.join(', ')}`
     )
   }
-  // If observer() is used in this file then we force cache to 'teamplay'
-  // TODO: this is a bit of a hack, think of a better way to do this
+  // Preserve the old import path shape for codebases that still use observer().
+  // The runtime behind that path no longer imports Teamplay.
   if (!cache && hasObserver) cache = 'teamplay'
   const reactType = state.opts.reactType
   if (reactType && !OPTIONS_REACT_TYPES.includes(reactType)) {

packages/babel-preset-cssxjs/index.js

@@ -2,8 +2,8 @@
 //            On React Native this should be passed.
 // reactType - force the React target platform (e.g. 'react-native', 'web'). Default: undefined.
 //                 This shouldn't be needed in most cases since it will be automatically detected.
-// cache - force the CSS caching library instance (e.g. 'teamplay'). Default: undefined
-//         This shouldn't be needed in most cases since it will be automatically detected.
+// cache - legacy compatibility option. 'teamplay' is still accepted but caching
+//         is owned by cssxjs internally.
 module.exports = (api, {
   platform,
   reactType,