Open items, and the standing rule about the derivation chain

Records the Dependabot PR to close and the manual-password decision to
confirm, plus the deferred hardening tiers and the gates still in force.

The part worth keeping visible: knownAnswer.test.ts failing is never "update
the expected value" -- it means the change is account-breaking. The rest of
the crypto suite only checks self-consistency, which stays green through
exactly the upgrade that would lock every user out.

Co-Authored-By: Claude Fable 5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01CMr9Yt8SYmZcfgrg3CV2G1

docs/TODO.md

@@ -0,0 +1,66 @@
+# BitLogin — open items
+
+Updated: 2026-07-31
+
+## Owner action items
+
+1. **Close the Dependabot PR on
+   `dependabot/npm_and_yarn/npm-security-and-maintenance-83024bc549`.** It
+   bundles seven major bumps into one change (`@noble/hashes` 1.8→2.2,
+   `@noble/curves` 1.9→2.2, `@scure/base` 1.2→2.2, `@scure/bip39` 1.6→2.2,
+   TypeScript 5→7, Vite 6→8, Vitest 3→4) and fails the build: noble v2 dropped
+   the extensionless subpath exports this code imports. It should be closed,
+   not merged or fixed — `.github/dependabot.yml` now groups only minor/patch
+   and ignores majors of the derivation chain, so this PR will not recur.
+
+   The four `dependabot/github_actions/*` PRs are unaffected and fine to merge.
+
+2. **Decide whether the manual-password removal is final.** User-chosen
+   passwords were removed entirely (not merely discouraged) in the 2026-07-31
+   hardening, and `packages/widget/src/securityPolicy.test.ts` pins that. The
+   security argument is sound — a user-chosen password against a downloadable
+   capsule is offline-guessable forever — but it is a product decision that
+   changes what users can do, and it is now enforced by a test rather than by
+   preference.
+
+## Standing rule: the derivation chain is a compatibility contract
+
+Account capsules live on public relays. The login name plus password derive the
+locator, signing scalar and capsule key deterministically, so those outputs are
+a contract with every account that already exists — change them and users are
+locked out permanently, with no server-side record to migrate from.
+
+`packages/core/src/crypto/knownAnswer.test.ts` pins HKDF-Extract, HKDF-Expand,
+ScalarExpand (scalar, counter, and resulting public key), BIP-39 phrase and
+seed, base64url framing, and JCS ordering.
+
+**A failure there is never "update the expected value".** It means the change
+being attempted is account-breaking and needs a migration plan or rejection.
+The rest of the crypto suite only checks self-consistency — same input, same
+output within one run — which stays green through exactly the kind of upgrade
+that would lock everyone out.
+
+## Deferred hardening
+
+Carried from the 2026-07-30 audit; none are live defects.
+
+- **Tier 2** — `packages/widget/src/element.ts` is ~1,600 lines with no direct
+  test coverage. `securityPolicy.test.ts` now asserts a few properties of its
+  source text, which is a start, not coverage.
+- **Tier 3** — compare-and-swap on capsule writes (relays offer no atomic
+  primitive, so this needs a protocol-level answer), and an encrypted
+  high-water-mark store.
+- **Tier 4** — moving high-value authorization into a cross-origin or extension
+  boundary. An embedded widget is same-origin with its host page, so a
+  compromised host can reach the worker directly. Documented honestly in
+  `llms.txt` and the README rather than papered over.
+
+## Gates still in force
+
+- **External security review before the vault holds anything beyond a
+  budget-capped NWC connection.** The S3 and password profiles stay designs
+  until then.
+- Personal-tier UI was gated on the sudo key leaving the credential capsule.
+  That gate is now **met** — the sudo key lives only in the phrase-gated
+  recovery capsule — but the UI still needs a separately reviewed key
+  ceremony before it ships.