echonet: chain parent hash from in-memory echonet blocks

[ron-starkware]

Resolve parent_block_hash from the latest in-memory stored block and fall back to the initialization base hash only when no blocks are stored.

Made-with: Cursor

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Note

Medium Risk
Changes block linkage (parent_block_hash) used by downstream consumers; incorrect resolution could break chain continuity in stored blocks, though the change is localized and has a clear fallback.

Overview
Echo Center now sets parent_block_hash for newly stored blocks by looking up the most recent in-memory block in SharedContext, instead of deriving it deterministically from the configured base.

This refactors DeterministicChain to expose compute_current_hash() (and base_block_hash_hex) and updates block/state_update transformations to use the new API, removing the prior combined current/previous-hash helper.

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[reviewable-StarkWare]

This change is 

[ron-starkware]

• echonet: Use Mainnet L1 Gas Prices #13514
• echonet: L1Manager Changes for Prices #13510
• echonet: Calculate committments #13309
• echonet: chain parent hash from in-memory echonet blocks #13308 👈 (View in Graphite)
• echonet: source block fields from feeder and blob #13307
• echonet: align receipt internal order with mainnet #13306
• main

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[ayeletstarkware]

@ayeletstarkware made 2 comments.
Reviewable status: 0 of 1 files reviewed, 2 unresolved discussions (waiting on ron-starkware).

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echonet/echo_center.py line 371 at r1 (raw file):

        }

    def _resolve_parent_block_hash(self) -> str:

what's the difference between this and the original func compute_current_and_previous_hash?

Code quote:

def _resolve_parent_block_hash(self) -> str:

[ron-starkware]

@ron-starkware made 2 comments.
Reviewable status: 0 of 1 files reviewed, 2 unresolved discussions (waiting on ayeletstarkware).

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echonet/echo_center.py line 371 at r1 (raw file):

Previously, ayeletstarkware (Ayelet Zilber) wrote…

what's the difference between this and the original func compute_current_and_previous_hash?

In compute_current_and_previous_hash it calculated the parent hash by doing +1 to the previous parent hash. Here, it takes the hash by looking at the previous block's hash (or the base block hash if there isn't one in the echonet storage)

[ayeletstarkware]

@ayeletstarkware reviewed 1 file and all commit messages.
Reviewable status: all files reviewed, 1 unresolved discussion (waiting on matanl-starkware).

[cursor]

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[matanl-starkware]

@matanl-starkware reviewed 1 file and all commit messages.
Reviewable status: all files reviewed, 1 unresolved discussion (waiting on ayeletstarkware).

[ron-starkware]

@ron-starkware resolved 1 discussion.
Reviewable status: complete! all files reviewed, all discussions resolved (waiting on ron-starkware).