@openuidev/react-ui@0.18.0

### Minor Changes

- [#1348](https://github.com/thesysdev/openui/pull/1348) [`9e76b1d`](https://github.com/thesysdev/openui/commit/9e76b1d0b48238e339918c5097f3adc54d88eba2) Thanks [@Aditya-thesys](https://github.com/Aditya-thesys)! - Add custom actions: `defineAction({ name, description, params })` plus `createLibrary({ actions })`. Programs use them like the built-in steps, alone or in `Action([...])`, for example `Button("Copy", @CopyToClipboard(order.id))`, with positional arguments in `params` key order. On click the step reaches the host `onAction` as `{ type: name, params }` (schema defaults applied), in order with the other steps, and the event is typed from the library so `params` narrows by `type`. Args are validated like library function args, and a step with invalid args is a no-op. Only a real call produces a custom step: a plan read from data (an object literal, `$state`, an `@Each` item) loses its custom steps, and a legacy action object whose type names a custom action is ignored. `library.toJSONSchema()` lists actions under `actions`, the prompt lists them with the built-in action steps, and `toSpec()` includes them. The React `Renderer` and the server autofix parser pick them up automatically, and the react-ui `Button` validates its form before a custom action.

  Types: the exported `ActionStep` union adds `{ type: "custom_action"; name; params }`, so a `switch` over `ActionStep` types needs a case for it.

  In react-ui, `AgentInterface` takes `onAction`, which receives the actions the chat does not handle itself, such as custom actions.

  The built-in steps (`@Run`, `@ToAssistant`, `@OpenUrl`, `@Set`, `@Reset`) are now defined like custom actions and live in the same call registry, so their prompt lines are generated too (for example `@OpenUrl(url: string)`). `ACTION_NAMES` is removed.

  A defined action has a `.ref` for slots that take only some actions, for example `share: z.union([copy.ref, steps.OpenUrl.ref]).optional()`: the prompt signature prints `share?: @CopyToClipboard | @OpenUrl`, and the JSON gets a `CopyToClipboard` `$defs` entry `{ type: "CopyToClipboard", params }`.

- [#1348](https://github.com/thesysdev/openui/pull/1348) [`9e76b1d`](https://github.com/thesysdev/openui/commit/9e76b1d0b48238e339918c5097f3adc54d88eba2) Thanks [@Aditya-thesys](https://github.com/Aditya-thesys)! - OpenUI Lang 1.0.

  - Upgrade `@openuidev/lang-core` and `@openuidev/react-lang` together, and together with the server that generates the system prompt. A 1.0 prompt teaches bare action steps (`@ToAssistant("Hi")` without `Action([...])`), which a 0.x client does not run.
  - react-ui 0.18 requires react-lang 1.0 (peer `>=1.0.0 <2.0.0`); upgrade them together.
  - browser-bundle 0.2 bundles react-lang 1.0 and react-ui 0.18.
  - server 0.3 uses lang-core 1.0 for autofix (parser and system prompt); stay on server 0.2 with a 0.x client. Autofix ignores warnings and accepts a ternary entry, so a program that renders does not start a fix round.
  - vue-lang, svelte-lang and angular-lang stay on 0.4 (OpenUI Lang 0.x). Keep `@openuidev/lang-core` ^0.4 for the prompts they render.
  - A program whose `root` statement is written last shows nothing while it streams, until the `root` line arrives. Write `root` first, as the system prompt asks.
  - A cut-off output that never reached its `root` statement, or any statement calling the root component, now renders blank instead of a partial tree.

### Patch Changes

- [#1348](https://github.com/thesysdev/openui/pull/1348) [`9e76b1d`](https://github.com/thesysdev/openui/commit/9e76b1d0b48238e339918c5097f3adc54d88eba2) Thanks [@Aditya-thesys](https://github.com/Aditya-thesys)! - Action steps are plans. Every step call now evaluates to a one-step plan (`{ steps: [step] }`), so a single step needs no wrapper: `Button("Ask", @ToAssistant("Tell me more"))`. Several steps still need `Action([...])`, for example `Button("Save", Action([@Set($saved, true), @ToAssistant("Saved")]))`; a plain list of steps stays a plain array. An invalid step evaluates to an empty plan (a no-op) instead of null, and `Action([...])` flattens nested plans. Legacy `{ type, params }` action configs are unchanged.

  New `action()` helper (lang-core, re-exported by react-lang), like `reactive()`: it returns the action prop schema, already tagged `ActionExpression`, so libraries write `action: action().optional()` instead of calling `tagSchemaId(..., "ActionExpression")` themselves. react-ui's action props use it.

  Prompt change: for libraries with action props (`ActionExpression`), the system prompt teaches one step bare and several steps in `Action([...])`. The react-ui prompt examples, including the chat library examples, use step calls instead of legacy objects.

- [#1348](https://github.com/thesysdev/openui/pull/1348) [`9e76b1d`](https://github.com/thesysdev/openui/commit/9e76b1d0b48238e339918c5097f3adc54d88eba2) Thanks [@Aditya-thesys](https://github.com/Aditya-thesys)! - Stored messages and Cloud responses whose second content line starts mid-line, after a cut-off first attempt, read the second attempt, as before.

- [#1348](https://github.com/thesysdev/openui/pull/1348) [`9e76b1d`](https://github.com/thesysdev/openui/commit/9e76b1d0b48238e339918c5097f3adc54d88eba2) Thanks [@Aditya-thesys](https://github.com/Aditya-thesys)! - `parseMessage` reads a content line that starts mid-line as a new content section, so a regenerated response wins over the cut-off one, also while streaming. react-lang and react-ui drop their own copies of this step, and a Cloud response keeps the second attempt's scripts.

- [#1348](https://github.com/thesysdev/openui/pull/1348) [`9e76b1d`](https://github.com/thesysdev/openui/commit/9e76b1d0b48238e339918c5097f3adc54d88eba2) Thanks [@Aditya-thesys](https://github.com/Aditya-thesys)! - OpenUI 1.0 review fixes:

  - lang-core: the built-in functions prompt no longer uses react-ui's `Col` in its `@Each` example, and names Query only when tool calls are on.
  - lang-core: `JSONSchemaDef` adds `type` and `anyOf`, so the CLI's spec for a library that uses `action()` passes to `generateSystemPrompt` without a cast.
  - react-ui: the chat prompt's button rules name `@ToAssistant` and `@OpenUrl`.
  - react-ui, a2ui, assistant-ui, devtools, react-email: the `@openuidev/react-lang` peer window now covers the version this release publishes.

- [#1348](https://github.com/thesysdev/openui/pull/1348) [`9e76b1d`](https://github.com/thesysdev/openui/commit/9e76b1d0b48238e339918c5097f3adc54d88eba2) Thanks [@Aditya-thesys](https://github.com/Aditya-thesys)! - The chat components read and write stored messages with `parseMessage` and `buildMessage` from react-lang instead of their own marker parser. Stored bytes are unchanged, and older messages in the `<content>`/`<context>` XML envelope still read. A complete message whose content ends in `]` (or any other start of a marker) is no longer cut short, and `]]>openui:end` text in the middle of a line stays in the content.

- [#1348](https://github.com/thesysdev/openui/pull/1348) [`9e76b1d`](https://github.com/thesysdev/openui/commit/9e76b1d0b48238e339918c5097f3adc54d88eba2) Thanks [@Aditya-thesys](https://github.com/Aditya-thesys)! - `@ToAssistant(message, context)` passes its context through unchanged as any value (object, array, number, string, including falsy ones). The `continue_conversation` step's `context` is now typed `unknown`, and react-lang forwards it in `params.context` whenever it is set. The react-ui chat adds it as the third element of the chat context, and card blocks append their item context to it as text, as before. The system prompt documents the context argument.
- Updated dependencies [[`9e76b1d`](https://github.com/thesysdev/openui/commit/9e76b1d0b48238e339918c5097f3adc54d88eba2), [`9e76b1d`](https://github.com/thesysdev/openui/commit/9e76b1d0b48238e339918c5097f3adc54d88eba2), [`9e76b1d`](https://github.com/thesysdev/openui/commit/9e76b1d0b48238e339918c5097f3adc54d88eba2), [`9e76b1d`](https://github.com/thesysdev/openui/commit/9e76b1d0b48238e339918c5097f3adc54d88eba2), [`9e76b1d`](https://github.com/thesysdev/openui/commit/9e76b1d0b48238e339918c5097f3adc54d88eba2), [`9e76b1d`](https://github.com/thesysdev/openui/commit/9e76b1d0b48238e339918c5097f3adc54d88eba2), [`9e76b1d`](https://github.com/thesysdev/openui/commit/9e76b1d0b48238e339918c5097f3adc54d88eba2), [`9e76b1d`](https://github.com/thesysdev/openui/commit/9e76b1d0b48238e339918c5097f3adc54d88eba2), [`9e76b1d`](https://github.com/thesysdev/openui/commit/9e76b1d0b48238e339918c5097f3adc54d88eba2), [`9e76b1d`](https://github.com/thesysdev/openui/commit/9e76b1d0b48238e339918c5097f3adc54d88eba2), [`9e76b1d`](https://github.com/thesysdev/openui/commit/9e76b1d0b48238e339918c5097f3adc54d88eba2), [`9e76b1d`](https://github.com/thesysdev/openui/commit/9e76b1d0b48238e339918c5097f3adc54d88eba2), [`9e76b1d`](https://github.com/thesysdev/openui/commit/9e76b1d0b48238e339918c5097f3adc54d88eba2)]:
  - @openuidev/react-lang@1.0.0
  - @openuidev/react-headless@0.18.0