fix: keep display names on unknown styled tags, and leave helpers alone

.changeset/named-import-helper-order.md

@@ -0,0 +1,5 @@
+---
+'babel-plugin-styled-components': patch
+---
+
+Helpers imported before `styled` in a named import are recognized now. In `import { css, styled } from 'styled-components'`, `css` and `keyframes` are minified, and with pure annotations turned on they are marked pure.

.changeset/require-non-tag-exports.md

@@ -0,0 +1,5 @@
+---
+'babel-plugin-styled-components': patch
+---
+
+A binding that is the styled factory keeps display names and component ids for properties this plugin does not recognize. On styled-components v7 that factory is a proxy, so `styled.box`, `styled.foo`, and `styled.feNotAFilter` are real components. `const styled = require('styled-components')`, `import sc from 'styled-components'`, `sc.default`, `ns.default`, and `__importDefault(require('styled-components')).default` are that factory. Known non-tag exports stay plain, including `sc.css`, `sc.keyframes`, `sc.createGlobalStyle`, `sc['createGlobalStyle']`, `sc.isStyledComponent`, and `sc.default.css`. Names on `Object.prototype` or `Function.prototype` stay plain too, including `sc.hasOwnProperty`, `sc.toString`, `sc.bind`, `sc.__lookupGetter__`, `sc.name`, and `sc.__proto__`. A computed key is resolved when it is a string, a template whose parts all fold to strings, or a const initialized to one of those, so `const name = 'css'; sc[name]`, `` sc[`css`] ``, and `` sc[`${'css'}`] `` stay plain, while `const css = 'div'; sc[css]` and `sc.default[css]` keep their ids. A key this plugin cannot resolve stays plain on `require()` and on an alias that is not named `styled`, so `let dynamic = 'css'; sc[dynamic]` returns the helper instead of throwing. `styled[dynamic]` on an import named `styled` is still decorated. A `let` or `var` that starts as the factory keeps its display name on a straight-line use written before the reassignment. A use inside a nested function, or inside a loop that also reassigns the binding, is left alone, so that function and the next loop iteration do not throw.

AGENTS.md

@@ -13,6 +13,7 @@ Commands
 - `pnpm build`: compile `src/` to `lib/`; run it to verify every set of changes. Don't start a dev server unless asked
 - `pnpm bench [--base <ref>] [--config default|all|bare] [--rounds N] [--normalize-aliases]`: interleaved A/B of the plugin at `<ref>` (default `origin/main`) against the working tree over generated inputs; fails when outputs differ
 - `pnpm bench:profile [--input small|medium|large|large-cjs]`: CPU profile with the plugin frames that drive Babel's work
+- `node scripts/compat.js [--base <ref>]`: styled-components v5, v6, and v7 prerelease smoke against the working tree and `<ref>` (default `origin/main`)
 - `pnpm style`: Prettier over `src/`
 - `pnpm changeset`: add a release note
 
@@ -86,6 +87,15 @@ Testing
 - Avoid snapshot churn. A change rewrites only the snapshots its behavior requires, and a hand-written expected output is changed only when the expectation itself was wrong, with the reason in the commit.
 - Jest `roots` is `test/`, so agent worktrees under `.claude/worktrees/` stay out of the run.
 
+Review
+
+- Every behavior change is checked against styled-components v5 (latest 5.x), v6 (latest 6.x), and v7 (latest prerelease dist-tag). `node scripts/compat.js` compiles smoke programs with the branch and with main, then executes the output (`renderToString` plus `ServerStyleSheet`) against each version. Generated CSS, displayName, and componentId match main except the intended change. No runtime errors.
+- Module formats: the plugin loads from CJS configs (`babel.config.js`, `.babelrc`) and ESM configs (`babel.config.mjs`, a `"type": "module"` project). Input covers ESM (default, named, aliased, and namespace imports) and CJS (`require`, `require(...).default`, destructured require). Babel's modules transform is checked both ways (preset-env `modules: false` and `'commonjs'`). Transformed output runs as native ESM and as CJS.
+- Known interop facts: v5 and v6 expose styled as `module.exports.default` and have no `exports` map, so a default import under native Node ESM yields the module object (a packaging limit, not a plugin bug). v7 `require()` returns the callable styled and that function is a proxy, so an unknown key is a component. A binding that is the factory (require, a default import, a named `styled` import, `.default` / `['default']` of a require or a namespace, and an interop default helper) decorates unknown properties and skips known non-tag exports and any key for which `name in Object.prototype || name in Function.prototype` (no DOM or SVG tag is on those prototypes). A namespace import uses the same member rules, because a CommonJS transform binds it to the module exports. A local that shadows the binding, or a use that appears after a reassignment, never receives `.withConfig`. A straight-line use in the binding's own scope that is written before the reassignment keeps its display name and component id. A use inside a nested function, or inside a loop that also reassigns the binding, stays plain, because that code can run after the assignment. A computed key resolves when it is a string literal, a template whose parts all fold to strings, or a const binding of those, and then uses the skip set. A key that does not resolve stays plain on a require or on an alias whose name is not the styled import's local name. `styled[dynamic]` and a default import's own local name stay decorated, matching the previous plugin, and that can throw if the runtime value is a helper.
+- A change to `isStyled` or the helper detectors is judged only after generating the full shape matrix: every import form (default, named, aliased, namespace, require, interop helper) x access form (dot, `.default`, computed literal, computed variable, call, `.attrs` / `.withConfig` chain, sequence) x export (intrinsic tags, known helpers, object methods, unknown names) x option preset. `node scripts/compat.js` runs a compact version of that matrix against v5, v6, and the latest v7 prerelease. A difference from the last release is a regression unless it is the intended fix.
+- Output changes (hash shifts, newly recognized forms, minify differences) need a changeset line even when intended.
+- Perf: run `pnpm bench` on main and the branch for changes that touch visitors or detectors. A slower branch is a regression.
+
 Performance
 
 - Hot-path code earns microbenchmarks before claiming it is optimized: A/B against the prior code at several input sizes (`pnpm bench`). Its run-to-run noise is large on big inputs, so repeat a run before trusting a single-digit difference. Babel plugins run per file per build, so per-node allocation and repeated AST walks matter.