chore: add Cursor AI rules

.cursor/rules/commit-messages.mdc

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+---
+description: Commit message format for web-editor
+alwaysApply: true
+---
+
+When generating a commit, the format should be:
+
+```
+CHANGE TYPE: SHORT TITLE
+
+DESCRIPTION OF EXPECTED IMPACT FOR END USER. DESCRIPTION OF THE CHANGES MADE.
+
+[TICKET NUMBER]
+```
+
+- `CHANGE TYPE` is one of `feat`, `chore`, or `fix`
+- `TICKET NUMBER` is in the format `AP-XXXX` — usually found in the branch name

.cursor/rules/components.mdc

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+---
+description: React component patterns for web-editor
+globs: **/*.tsx
+alwaysApply: false
+---
+
+# Components
+
+- Use function components with hooks instead of class components.
+- Use the `FC` type rather than `FunctionComponent`.
+- Wrap all components with `observer()` from `mobx-react`.
+- Use named exports for components, not default exports.
+- Use a named function for the component; the function name should match the component name:
+  ```tsx
+  const Cmpt: FC<Props> = observer(function Cmpt(props: Props) {
+    return <div />;
+  });
+  ```
+- Never use barrel files (`index.ts` re-exports). Always use direct imports to the specific file.
+
+## Base Practices
+- For components exceeding 150 lines, extract sub-components into separate files.
+- Remove props that can be derived from other props.
+
+## Styling
+- Prefer `makeStyles()` over inline styles or `sx` props.
+- Always include a `name` option in `makeStyles` matching the component name.
+- Keep styles in the same file as the component.

.cursor/rules/general.mdc

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+---
+description: TypeScript/Node.js coding standards for web-editor
+alwaysApply: true
+---
+
+# Web Editor — General Standards
+
+## Language & Style
+- Use **TypeScript** throughout. No plain `.js` files in source.
+- Follow **AirBnB ESLint** rules for all TypeScript and JavaScript.
+- Always remove unused imports.
+- Be as focused and concise as possible — check existing files before creating new ones.
+
+## Project Context
+- This is the Evolv visual editor, hosted inside the Aetherial Docker desktop environment.
+- It communicates with Aetherial via **AWS SQS** — the command queue receives actions (e.g. `create_metamodel`) and the response queue returns results.
+- SQS message schema changes must be coordinated with the `aetherial` repo.
+
+## Build & Dev
+- Package manager: **npm** (npm workspaces).
+- Build workspace dependencies before starting: `npm run build:deps`
+- Start the dev server: `npm start`
+- Always run `npm run type-check` and `npm run lint` before committing.
+
+## Error Handling
+- Never fail silently. Missing required env vars or config must throw at startup.
+- Log errors with sufficient structured context to debug issues without a debugger.

.cursor/rules/git-linear-workflow.mdc

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+---
+description: Git hygiene and Linear workflow standards for web-editor
+alwaysApply: true
+---
+
+# Git Hygiene
+
+## Branch Naming
+- Prefer `feature/AP-123-short-slug`, `fix/AP-123-short-slug`, or `chore/AP-123-short-slug` when working from a Linear ticket.
+- Always include the Linear issue key in the branch name when one exists.
+
+## Pull Requests
+- Include the Linear issue key in the PR title.
+- Link the issue in the PR description.
+- Keep PRs focused to one concern.
+- Ensure `npm run type-check` and `npm run lint` pass before requesting review.
+- Always use `GH_PAGER=cat` for `gh` commands.
+
+# Linear Workflow
+
+## Before Starting Work
+1. Search for an existing Linear issue first.
+2. Assign to yourself and move to `In Progress` before writing code.
+3. Ensure acceptance criteria are explicit checklist items.
+
+# Linear Access
+- Use the `linear` CLI for Linear operations instead of Linear MCP tools.

.cursor/rules/state-management.mdc

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+---
+description: State management patterns for web-editor
+globs: **/*.ts,**/*.tsx
+alwaysApply: false
+---
+
+# State Management
+
+- Use **MobX** for app-wide state management.
+- Prefer method syntax over arrow functions in classes where binding isn't required.
+- Prefer `useStaticValue` over `useState` for stores and values that never change after the initial render.
+- Use `useDisposable()` rather than `useState()` for objects that implement `Disposable`.