docs(adr): add ADR-0032, structured Workshop editor form factor and stack

[e54-bot]

Summary

Adds ADR-0032. It decides the form factor that ADR-0029 left open for a structured editing view: what the view is, where it lives, and how it is built.

• Form factor: wright ui [INPUT] serves a local web UI on loopback and opens it in the browser. It is not a hosted service, an editor extension, or a desktop shell.
• Scope: raw Workshop projects, the same scope as ADR-0029. Other inputs are refused with the owner named.
• Adapter, like MCP (ADR-0020):
  • The page sends wright-agent/v1 bodies to one local endpoint and gets the results back unchanged.
  • The UI has no Workshop semantics of its own.
  • The endpoint is not a public transport.
• Local endpoint security:
  • Binds 127.0.0.1 on an ephemeral port.
  • Every request needs a per-session token, passed to the page in the URL fragment.
  • Requests with a foreign Host or Origin are refused. No CORS headers.
• Writes: wright ui applies the editStatements transaction after re-checking inputIdentity. The page never touches files.
• Ownership: a top-level ui/ directory in wright, outside the Rust workspace.
• Stack: Svelte 5 in project-wide runes mode, strict TypeScript, and Vite.
  • The only runtime dependency is svelte.
  • Every value that leaves the reactive tree goes through $state.snapshot.
  • React was rejected. Preact with signals was the close alternative.
• Types: generated from schemas/wright-agent-v1.schema.json and workshop-rs's rule-content-v1.schema.json. A stale copy fails CI.
• Build and distribution:
  • Assets are built in ui/, not committed, and embedded behind a ui Cargo feature that release builds enable.
  • Without the feature, wright ui reports that the build has no UI and exits 2. Rust-only builds need no Node.
  • Release channels are unchanged.
• Verification:
  • A UI CI job runs svelte-check, unit tests, the build, and a 100 KB gzip size budget.
  • An end-to-end headless-browser test edits a fixture and checks the bytes on disk.
• Delivery in layers: read-only first, then editing (editStatements), then full dropdowns (listEntries).

Why now

The prototype (practice-range, 139 rules) covers the interaction end to end. It also shows the limits of plain JavaScript: the whole form is rebuilt after every change, and untyped nodes caused real defects. Its only link to Wright is a Python bridge, because a browser cannot reach wright serve over stdio.

Review

Accepted by the owner. The four open points were accepted as drafted: the command name wright ui, the ui Cargo feature with exit 2 when it is absent, the 100 KB gzip size budget, and host-side writes in decision 5.

Documentation only; no code or behavior changes.