Say what the verification, erasure and sealed claims actually establish

[404SecNotFound]

Summary

The assurance language is corrected where it claimed more than the code or the evidence supports, and a brief for a review of the current format is added. A sweep of every doc and UI string found about 60 assurance claims. Each change below was checked against the source before editing. Based on main. It refers to roadmap 9.x, which #223 adds, but does not conflict with #223 or #224.

Changes

Claims corrected

Where	Said	Now says
Docs guide, verify-only diagram	the plaintext is discarded in the worker	it comes back to the page, which zeroes it unshown (9.2)
SECURITY-AUDIT.md, roadmap 2.1	passwords and plaintext live in the worker's heap	derived keys do; a dated correction says what crosses
Roadmap 2.3	authenticating AEAD requires producing the plaintext	the tags need only the ciphertext, but the APIs the app calls verify by decrypting
Auto-lock toasts, dice tool	secrets "wiped from memory", "clear the log from memory"	cleared from the page
Sealed status label	"nothing leaves"	"no connections", which is what the policy check proves
In-place build check	"N of N cached files match", silently skipping files not cached	also says how many of the manifest's files were not checked, and that a manifest from the same place shows consistency, not origin
Verify page, VERIFYING.md, HOW-IT-WORKS.md, README	verification proves "the bytes you ran" match; sha256sum checks the signature; "the audit" says whether the source is right	the files you downloaded; the signature needs an identity from outside the site; the review on record does not cover the current format
Inspector	"a removed slot can't hide"	"a change made without a key is reported" (a slot holder can re-seal the table)
Page metadata	keyword "zero knowledge"	removed, as OUTREACH.md already rules out

SECURITY-AUDIT.md keeps its record and gains a dated correction note, not a silent rewrite. It still names none of the current-format subjects, so the README gate's scope check holds.

New: docs/AUDIT-BRIEF.md. It sets out what a reviewer of the current format needs:

• the scope, pointing at the normative sections;
• what is out of scope;
• each adversary, with the documented position or an explicit question;
• the evidence and its counts;
• the open findings;
• questions for the reviewer;
• a claim register linking each security claim to its evidence and to what it rests on.

Needs an owner decision

The repository describes its reviews two ways.

• SECURITY-AUDIT.md calls its findings "external review", and one section a "Third-party audit (four-agent swarm)".
• OUTREACH.md says the project is "Not audited" and has a self-audit.
• The README says parts of the current format have been through "external review passes".

Only you know who performed them. The brief states the conflict and asks readers not to treat those findings as independent assurance until you settle it. I did not change the audit's or the README's characterisation.

Test plan

• typecheck, test:readme, test:release-notes, test:release-gate, test:release-recipe, test:seal-verdict and test:csp-egress pass.
• tests/browser/sealed-status.spec.ts now checks the unchecked-file count against the manifest on disk. On the real build the manifest lists files the cache does not hold, so that branch is exercised. It also checks the origin caveat.
• Negative controls, each typechecked and built before its result was read, with files restored and checked by checksum. Hiding the unchecked-file count fails the test ("the result hid the files it did not check"). Dropping the origin caveat fails it too.
• Chromium full suite: 310 passed, 5 skipped, exit 0.
• Firefox and WebKit run in this PR's CI.

Not done here

• Changelog entry. It is left out so this PR does not conflict with Derive every description of a backup's ways in from one access policy #224, which opens the Unreleased section. It can follow once Derive every description of a backup's ways in from one access policy #224 merges.
• Committed screenshots. Any that show the old "nothing leaves" label are not regenerated. test:screenshots checks widths only.
• Internal design notes (docs/design/). These are planning documents, and their similar wording is left as written.