Fix auth mutation client typing

[zbeyens]

• Auto release

🐛 Fixes #243
🟢 95-100% confidence

Phase	🧪 Tests	🌐 Browser
Reproduced	🔴 Type regression failed with getSession assignability error	➖ N/A
Verified	🟢 Regression passed; bun check green	➖ N/A

✅ Outcome

• createAuthMutations(authClient) accepts Better Auth clients using convexClient().
• No user casts.
• Patch changeset added.
• Existing Better Auth 1.6 solution note refreshed.
• Watcher test made deterministic after full gate exposed flake.

⚠️ Caveat

• No browser surface. TypeScript/package behavior only.

🏗️ Design

• Chosen seam: createAuthMutations structural auth method boundary.
• Why not quick patch: casting user auth clients exports package compat debt into app code.
• Why not broader change: convexClient() runtime shape was right; replacing the auth client surface was unnecessary.

🧪 Verified

• bun lint:fix
• bun typecheck
• bun --cwd packages/kitcn build
• bun test packages/kitcn/src/react/auth-mutations.types.test.ts packages/kitcn/src/react/auth-mutations.test.tsx
• bun test packages/kitcn/src/cli/watcher.test.ts -t "startWatcher reacts to a real file change with chokidar v5"
• bun check

[changeset-bot]

🦋 Changeset detected

Latest commit: f946acd

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 2 packages

Name	Type
kitcn	Patch
@kitcn/resend	Patch

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Project	Deployment	Actions	Updated (UTC)
better-convex	Ready	Preview, Comment	Apr 26, 2026 0:00am