Make browser confirmation conservative by default

[vsolano9]

What & why

The confirmation gate trusts recipe authors to label only clicks with write: true. That allows a mutating goto, typing, an unlabeled click, or even write: false to reach the browser without confirmation. This adopts the issue’s conservative-by-default option: recipes run unconfirmed only when every step is provably read-only.

Closes #3

Changes

• treat typing, every click, and navigation away from the canonical entry URL as confirmation-required
• keep only waits and redundant canonical entry navigation on the unconfirmed path
• retain the legacy write field for recipe compatibility without allowing it to waive confirmation
• return an action-neutral confirmation error at the request boundary
• align README, runnable example, source comments, and assistant context with the enforced contract
• add an exhaustive nine-scenario gate table exposed through npm test

Validation

• RED: path/query navigation, typing, unlabeled click, and write: false click all bypassed the old gate
• npm test — 10/10 pass; repeated successfully 20 consecutive times
• Node 20 test run — 10/10 pass
• local Wrangler /run integration — mutating goto, type, and write:false click each return the exact HTTP 400 confirmation error before browser launch
• npm run typecheck — pass
• npx wrangler deploy --dry-run — pass; no deployment
• git diff --check — pass
• fresh npm ci — pass; reports the existing dependency advisories (10 total, 4 high in production dependencies); no dependency or lockfile changes

Checklist

• Focused change with a clear description
• Ran format / lint / tests (repository provides typecheck and tests; both pass)
• Updated docs or CHANGELOG if relevant
• Linked the related issue