docs(upgrades): rename Cobalt B20 pages, add Denim B20 upgrade pages

[roethke]

What changed? Why?

Feedback from the B20 team (Stephan) on the Upgrades sidebar.

Cobalt: renamed pages

Before	After
B20: Beryl to Cobalt Migration	B20: ERC-8056 Conformant Multiplier
B20: Seize Surface and burnBlocked Deprecation	B20: Seize Functionality

Only the titles change. URLs stay the same, so no redirects are needed.

Cobalt multiplier page: statuses matched to base-std. The mapping table labeled multiplier() and scaledBalanceOf(address) "deprecated-name-kept". base-std marks both "unchanged (canonical name)", with uiMultiplier() / balanceOfUI(address) as ERC-8056 aliases. The table and migration paragraph now say so. Found in review of #2026. B20 team: please confirm.

Denim: 3 B20 pages that were missing

The base-std specs in changelog/03_Denim_* (as of base-std@1505323) had no pages in Upgrades > Denim:

• 03-denim-b20-token-receiver: transfer, mint, and seize to the token's own address revert InvalidReceiver. Breaking.
• 03-denim-b20-transfer-executor-enforcement: TRANSFER_EXECUTOR_POLICY applies to every transfer path. Breaking for tokens that already set a restrictive executor policy.
• 03-denim-policyregistry-not-policy: bit 63 of a policy ID inverts isAuthorized. Non-breaking.

Also:

• Denim overview: new "B20 Improvements" accordion that links to the 3 pages
• B20 changelog summary (specifications/b20/changelog): new Denim ordinal row and section
• llms.txt, llms-full.txt, AGENTS.md: regenerated

Notes to reviewers

• Overlap with sync PRs: the base-std sync automation opened docs: feat(b20): reject the token itself as a credit recipient (base-std@1505323) #1991 (token receiver) and docs: feat(policy): add NOT/invert policy semantics to reference (base-std@91427ab) #1973 (NOT policy). Both have been open for 1–2 weeks and also touch ~20 other reference pages. Nothing was generated for transfer executor enforcement: docs: feat(policy): enforce TRANSFER_EXECUTOR_POLICY on every transfer path (base-std@253bb15) #1968 updated only the reference pages, not an Upgrades entry. This PR adds the 3 Upgrades pages only. If it merges first, the matching changelog files in docs: feat(b20): reject the token itself as a credit recipient (base-std@1505323) #1991 and docs: feat(policy): add NOT/invert policy semantics to reference (base-std@91427ab) #1973 will conflict; take this PR's version and keep their reference-page edits.
• Example fix in the NOT-policy page: the base-std spec example inverts a sanctions BLOCKLIST and calls the result "not sanctioned". Inverting a blocklist actually authorizes only sanctioned accounts. This page uses an ALLOWLIST of sanctioned addresses, which gives the intended result. The same fix should go upstream in base-std.
• Where this PR departs from the base-std spec text, it follows base-std's reference code and tests:
  • NOT policy gas: the spec says an inverted query adds "no extra SLOAD". MockPolicyRegistry._isAuthorized runs _policyExists(base) before recursing, so an inverted simple policy reads the base record and then the membership bit. The page now describes the existence guard and drops the no-extra-SLOAD claim. The spec text should be corrected upstream, or the mock changed if the claim is the intended design.
  • Built-in children: the page adds a row for ALWAYS_ALLOW_ID / ALWAYS_BLOCK_ID as composite children (InvalidChildPolicy, per test_createCompositePolicy_revert_builtinChild).
  • Executor revert order: the spec's Denim column says "zero-receiver". The token-receiver spec and transfer_revertOrder.t.sol call that step INVALID-RECEIVER at Denim, so the page uses invalid-receiver.
  • Solidity examples: the spec examples use array literals ([transferAgent]) and bare enum names (ALLOWLIST), which don't compile against IPolicyRegistry. The pages use address[] / uint64[] memory arrays and IPolicyRegistry.PolicyType.*.
• Changelog summary Note: it said behavior never changes and the standard only grows by addition. Two Denim entries are breaking, so the Note now says selectors don't change but behavior can change at a hardfork. Both entries are tagged "(Breaking)", matching the base-std titles.
• Linked reference pages: transfer, seize-with-memo, and transfer-executor-policy still describe pre-Denim behavior until docs: feat(b20): reject the token itself as a credit recipient (base-std@1505323) #1991 / docs: feat(policy): enforce TRANSFER_EXECUTOR_POLICY on every transfer path (base-std@253bb15) #1968 land. The changelog pages now say so instead of calling them "current".
• Selectors checked with cast sig: invertedPolicyId(uint64) = 0x6b468933, InvalidReceiver(address) = 0x9cfea583.

How has it been tested?

• node scripts/validate-docs-structure.js: passes (nav, orphans, redirects, route table)
• node scripts/lint-mdx.js: 0 errors on every changed page. --check-nav shows 6 file-not-found errors that are already on master and unrelated to this PR.

Screenshots

TODO: run /screenshot on the Denim and Cobalt sidebar groups and the 3 new pages.

[mintlify]

Preview deployment for your docs. Learn more about Mintlify Previews.

Project	Status	Preview	Updated
base	🟢 Ready	View Preview	Sep 28, 2026, 9:57 PM

💡 Tip: Enable Automations to automatically generate PRs for you.

[cb-heimdall]

🟡 Heimdall Review Status

Requirement	Status	More Info
Reviews	🟡 0/1	Denominator calculation Show calculation 1 if user is bot 0 1 if user is external 0 2 if repo is sensitive 0 From .codeflow.yml 1 Additional review requirements Show calculation Max 0 0 From CODEOWNERS 0 Global minimum 0 Max 1 1 1 if commit is unverified 0 Sum 1