feat(foundations): update config for [04.2026] release

foundations/config.mdx

@@ -462,6 +462,99 @@ For up-to-date values, see [https://tonviewer.com/config](https://tonviewer.com/
 
 [Parameter #29 on mainnet](https://tonviewer.com/config#29)
 
+## Param 30: consensus extension
+
+<Aside type="note">
+  The [TON v2026.03](https://github.com/ton-blockchain/ton/releases/tag/v2026.03) update introduced this parameter on testnet. With the [TON `v2026.04`](https://github.com/ton-blockchain/ton/releases/tag/v2026.04) update, `ConfigParam 30` was enabled on mainnet.
+</Aside>
+
+This parameter stores optional per-workchain settings for the [Simplex](https://github.com/ton-blockchain/simplex-docs/blob/main/Simplex.md)-based Catchain 2.0 consensus path. It does not fully replace `ConfigParam 29`: the node still uses `max_block_size` and `max_collated_data_size` from the `ConfigParam 29`.
+
+The `crypto/block/block.tlb` [defines](https://github.com/ton-blockchain/ton/blob/v2026.04/crypto/block/block.tlb#L782) the following schema:
+
+```tlb
+simplex_config#21 flags:(## 7)
+  use_quic:Bool
+  target_rate_ms:uint32
+  slots_per_leader_window:uint32
+  first_block_timeout_ms:uint32
+  max_leader_window_desync:uint32
+  = NewConsensusConfig;
+
+simplex_config_v2#22 flags:(## 7)
+  use_quic:Bool
+  slots_per_leader_window:uint32
+  noncritical_params:(HashmapE 8 uint32)
+  = NewConsensusConfig;
+
+new_consensus_config_all#10
+  mc:(Maybe ^NewConsensusConfig)
+  shard:(Maybe ^NewConsensusConfig)
+  = NewConsensusConfigAll;
+
+_ NewConsensusConfigAll = ConfigParam 30;
+```
+
+There are two optional refs in `new_consensus_config_all#10`. If a ref is absent, then the pre-2.0 Catchain config is active for the corresponding class of chains:
+
+| Field   | Type                        | Meaning                                                 |
+| ------- | --------------------------- | ------------------------------------------------------- |
+| `mc`    | `Maybe ^NewConsensusConfig` | Config for the masterchain (`workchain = -1`)           |
+| `shard` | `Maybe ^NewConsensusConfig` | Config for shardchains (all non-masterchain workchains) |
+
+The `NewConsensusConfig` has two constructors:
+
+- `simplex_config#21` is the legacy fixed-layout format; scheduled for removal.
+- `simplex_config_v2#22` is the current extensible format, which supports arbitrary `noncritical_params` without changes to the `block.tlb` layout.
+
+The `simplex_config_v2#22` constructor moves noncritical configuration parameters into a sparse dictionary:
+
+```tlb
+simplex_config_v2#22 flags:(## 7)
+  use_quic:Bool
+  slots_per_leader_window:uint32
+  noncritical_params:(HashmapE 8 uint32)
+  = NewConsensusConfig;
+```
+
+### Configuration parameters of `simplex_config_v2`
+
+- `flags`: A general field that can be used to set various binary parameters.
+- `use_quic`: Whether the QUIC transport is used instead of RLDP2. Set to **True** in mainnet.
+- `slots_per_leader_window`: Number of consecutive slots assigned to one leader. Set to **4** in mainnet.
+- `max_block_size = 4 MiB`
+- `max_collated_data_size = 4 MiB`
+- `noncritical_params`: A `HashmapE 8 uint32` map from parameter IDs to raw 32-bit values.
+
+The `noncritical_params` dictionary contains tunable timing and DoS-protection parameters that might differ between validators:
+
+- The key is an 8-bit parameter ID.
+- The value is always a raw 32-bit word.
+- Unknown IDs are ignored by the current implementation.
+- Missing IDs use default values.
+- Duration-like parameters store milliseconds directly.
+- Floating-point parameters store `float32` bits according to the [IEEE-754](https://en.wikipedia.org/wiki/IEEE_754) standard in a `uint32` value. The loader then reinterprets these bits as a floating-point numeric value.
+
+IDs from `0` through `14` are recognized and supported. On the mainnet, only IDs `0`, `1`, and `13` are explicitly set. All other IDs are normally absent and use defaults.
+
+| ID   | Name                                   | Stored as                  | Default                | Meaning                                                                                                    |
+| ---- | -------------------------------------- | -------------------------- | ---------------------- | ---------------------------------------------------------------------------------------------------------- |
+| `0`  | `target_rate`                          | `uint32` milliseconds      | `2400 ms`              | Target slot or block interval; used for leader pacing, block production timing, and skip scheduling.       |
+| `1`  | `first_block_timeout`                  | `uint32` milliseconds      | `1000 ms`              | Base timeout before skip voting starts for the first missing block in a leader window.                     |
+| `2`  | `first_block_timeout_multiplier`       | `float32` bits in `uint32` | `1.2`                  | Multiplier applied to `first_block_timeout` after a window that had skips.                                 |
+| `3`  | `first_block_timeout_cap`              | `uint32` milliseconds      | `100000 ms`            | Cap for the adaptive `first_block_timeout` growth.                                                         |
+| `4`  | `candidate_resolve_timeout`            | `uint32` milliseconds      | `1000 ms`              | Initial timeout for candidate or notarization resolution requests.                                         |
+| `5`  | `candidate_resolve_timeout_multiplier` | `float32` bits in `uint32` | `1.2`                  | Backoff multiplier for candidate resolution retries.                                                       |
+| `6`  | `candidate_resolve_timeout_cap`        | `uint32` milliseconds      | `10000 ms`             | Cap for candidate resolution timeout growth.                                                               |
+| `7`  | `candidate_resolve_cooldown`           | `uint32` milliseconds      | `10 ms`                | Cooldown between candidate resolution attempts.                                                            |
+| `8`  | `standstill_timeout`                   | `uint32` milliseconds      | `10000 ms`             | No-progress timeout before standstill recovery or rebroadcast logic triggers.                              |
+| `9`  | `standstill_max_egress_bytes_per_s`    | `uint32` number            | `6553600` (`50 << 17`) | Egress rate cap used during standstill rebroadcast.                                                        |
+| `10` | `max_leader_window_desync`             | `uint32` number            | `250`                  | Maximum tolerated future leader-window distance for inbound Simplex traffic.                               |
+| `11` | `bad_signature_ban_duration`           | `uint32` milliseconds      | `5000 ms`              | Temporary ban duration after receiving bad signatures from a peer.                                         |
+| `12` | `candidate_resolve_rate_limit`         | `uint32` number            | `10`                   | Per-peer rate limit for candidate resolution requests.                                                     |
+| `13` | `min_block_interval`                   | `uint32` milliseconds      | `0 ms`                 | Minimum interval between parent block time and the next locally generated block.                           |
+| `14` | `no_empty_blocks_on_error_timeout`     | `uint32` milliseconds      | `15000 ms`             | How long empty-block fallback is allowed after the last finalized block when collation fails or times out. |
+
 ## Param 31: fee-exempt contracts
 
 This parameter represents the configuration of smart contract addresses from which no fees are charged for either gas or storage, and where **tick-tock** transactions can be created. The list usually includes governance contracts. The parameter is presented as a binary tree structure — a tree (HashMap 256), where the keys are a 256-bit representation of the address. Only addresses in the masterchain can be present in this list.