Cardano Updates

Move the GitHub Pages theme from the old violet/navy palette to the
Cardano Foundation developer-portal visual language
(developers.cardano.org): Cardano Blue (#0033AD) on generous white
space, clean Inter typography, soft rounded cards, minimal shadows.

- custom.css: Cardano-blue accent ramp; light mode is now the primary
  aesthetic (white + blue), dark mode a blue-tinted deep navy; branded
  splash hero with a soft blue gradient + gradient headline; pill-shaped
  CTA buttons; rounded card grid with blue icons and hover lift.
- Add a Cardano-blue brand mark (src/assets/logo.svg) and wire it into
  the Starlight header; refresh the favicon to match.

Built clean: 13 pages, brand color + logo present in output, no
easy1staking self-references in the rendered site.

Co-Authored-By: Claude Fable 5 <[email protected]>

Signed-off-by: cryptodj413 <[email protected]>

- Fix issue that stake delegations to retired pools were not being
  removed.
- Stylize the rule to follow that of the Conway and previous specs.

A failed `git config` write (e.g. read-only `.git`) was swallowed by
`|| true`, leaving only Git's confusing raw error with no hint the `treefmt`
hook was skipped.

Messaging with a read-only `.git`:

- before:

  ```
  error: could not lock config file .git/config: Read-only file system
  ```

- after:

  ```
  error: could not lock config file .git/config: Read-only file system
  note: couldn't set git core.hooksPath (is .git read-only?)
  hint: the blockfrost-platform pre-commit (treefmt) hook was not installed
  ```

Test with 9.14.2

When a CertRB header arrives via ChainSync, recognise it
(headerContainsLeiosCert) and offer the EB it certifies
(chainDepStateLeiosAnnouncement) to that peer's LeiosFetch state, as if its
LeiosNotify client had offered it (leiosCertRbCallback / leiosCertRbOffer). The
per-peer LeiosPeerVars are now a shared, get-or-create resource: every peer-vars
mini-protocol (ChainSync, LeiosNotify, LeiosFetch) wraps itself in
bracketLeiosPeer, which allocates the entry if absent and cleans it up on exit.

Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>

Treat a missing EB closure like a missing predecessor. ChainSel's
candidate construction skips a CertRB whose announced EB closure is not yet in
the ChainDB-owned acquired set (cdbAcquiredLeiosEbs, seeded at open and grown by
leiosAcquiredEbsRunner from LeiosDb closure-completion notifications). When a
closure arrives, a FIFO ChainSelReprocessLeiosEb message reprocesses the
announcer RBs' cert-carrying successors (found via getLeiosAnnouncers). Also
drives LeiosDb GC/promotion and prunes the acquired set at GC-schedule time.

Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>

Add three methods to LeiosDbHandle (implemented for the in-memory and SQLite
backends): leiosDbScanCompleteEbClosuresNotOlderThanSlot (used at ChainDB open
to seed the acquired-EB-closures set, incl. restart recovery), and the still
no-op leiosDbGarbageCollect and leiosDbPromoteToImmutable lifecycle hooks. Inert
until ChainDB calls them.

Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>

Add biHasLeiosCert and biLeiosAnnouncedEb to BlockInfo, derived in
extractBlockInfo via blockHasLeiosCert / headerLeiosAnnouncement (hence a
ResolveLeiosBlock constraint on the VolatileDB and its openDB callers, e.g.
DBImmutaliser). Add an incremental EB-announcer reverse index
(LeiosAnnouncerIndex) maintained alongside currentSuccMap, exposed as
getLeiosAnnouncers. Inert until ChainSel consumes it.

Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>

Add two methods to ResolveLeiosBlock (both with no-Leios defaults):
headerContainsLeiosCert, which reads the header's hbLeiosContainsCert bit so a
CertRB is recognisable from its header alone, and chainDepStateLeiosAnnouncement,
which reads the EB a CertRB certifies from the predecessor's chain-dep state.
Implement them for the Shelley Dijkstra and CardanoBlock instances (the latter
projecting its chain-dep state), factoring out praosLeiosAnnouncement.

Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>

Add hbLeiosContainsCert to the Praos HeaderBody (Dijkstra-only; 10-vs-12-field
CBOR encoding so pre-Leios blocks stay byte-identical), thread it through
mkHeader and Shelley forging, and expose it via pHeaderLeiosContainsCert on the
protocol-header abstraction (TPraos uses default_pHeaderLeiosContainsCert =
const False). Enforce the header/body envelope in blockMatchesHeader: the cert
bit is set iff the body carries exactly one Leios certificate and no txs.

No ChainSync callback yet; that arrives with the peer-vars lifecycle.

Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>

Vote on the hash of the ranking block that announced the EB instead of the
LeiosPoint, which comprises the slot number and EB hash. This forbids reusing
Leios certificates across Praos forks.

Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>

ZK on Cardano has live on-chain primitives (BLS12-381 builtins) and shipped proofs of concept but no home in the curriculum. Add a concept-first earmark under advanced smart contracts, flagged as in active development.

Module 3 already names the gap (native tokens have no built-in transfer logic) but dead-ends there. Add a concept-first earmark for CIP-113: what transfer-time validation buys you, the shared-script and stake-credential model, and an honest in-development status that links out to the reference implementation.

The page gave Mesh's AI context a co-equal section, pushing one SDK ahead of the aggregation layer we want people to start with. Lead with Cardano Dev Skills as the tool-agnostic default and demote Mesh to an optional, SDK-specific deepening.