fix: check of unexpected file too eager on all network except devnet

[Alenar]

Content

This PR make the unexpected download verifier to always expect immutable files starting from 0 on all network.

After checking it appears that all network starts at 0, but it was expecting the first immutable to be 1 on network that were not devnet, meaning that the first immutable files trio was removed after download, making impossible for the message verifier to compute the expected message.

Note: as this remove what was expected to be a business case, this change allow to simplify the unexpected download verifier api and code a bit.

Pre-submit checklist

• Branch
  • Tests are provided (if possible)
  • Crates versions are updated (if relevant)
  • Commit sequence broadly makes sense
  • Key commits have useful messages
• PR
  • All check jobs of the CI have succeeded
  • Self-reviewed the diff
  • Useful pull request description
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• Documentation
  • No new TODOs introduced

Issue(s)

Relates to #2429

[Copilot]

Pull Request Overview

This PR fixes the unexpected download verifier so that it always expects immutable files starting at 0 for all networks, simplifying the API and code.

• Removed the redundant network parameter and related logic in UnexpectedDownloadedFileVerifier.
• Updated tests and usage in SnapshotClient and InternalDownloader accordingly.

Reviewed Changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated no comments.

File	Description
mithril-client/src/utils/unexpected_downloaded_file_verifier.rs	Removed network-specific behavior and updated tests/docs.
mithril-client/src/snapshot_client.rs	Removed outdated network parameter from verifier invocation.
mithril-client/src/cardano_database_client/download_unpack/internal_downloader.rs	Removed redundant network parameter from verifier call.

Comments suppressed due to low confidence (2)

mithril-client/src/utils/unexpected_downloaded_file_verifier.rs:15

• Update the module-level comment to reflect the new behavior that immutable file numbers now always start at 0 and remove any reference to devnet-specific logic.

//!   * networks: immutables file numbers start at 1 on most network, but 0 on devnet

mithril-client/src/utils/unexpected_downloaded_file_verifier.rs:214

• [nitpick] Revise the test case comments to state that the expected range always begins at 0, since the network distinction has been removed.

// Specs:

[github-actions]

Test Results

    3 files  ±0     77 suites  ±0   15m 17s ⏱️ -37s
1 929 tests  - 2  1 929 ✅  - 2  0 💤 ±0  0 ❌ ±0 
3 272 runs   - 6  3 272 ✅  - 6  0 💤 ±0  0 ❌ ±0 

Results for commit 615a138. ± Comparison against base commit 623dbe8.

This pull request removes 4 and adds 2 tests. Note that renamed tests count towards both.

mithril-client ‑ utils::unexpected_downloaded_file_verifier::tests::compute_expected_state_after_download::when_dir_empty_return_empty_if_immutable_files_dir_does_not_exist_and_range_is_empty
mithril-client ‑ utils::unexpected_downloaded_file_verifier::tests::compute_expected_state_after_download::when_dir_empty_return_empty_if_immutable_files_dir_exist_and_range_is_empty
mithril-client ‑ utils::unexpected_downloaded_file_verifier::tests::compute_expected_state_after_download::when_immutable_files_dir_does_not_exist_return_immutables_trios_if_immutable_files_range_is_not_empty
mithril-client ‑ utils::unexpected_downloaded_file_verifier::tests::compute_expected_state_after_download::when_immutable_files_dir_empty_return_immutables_trios_if_immutable_files_range_is_not_empty

mithril-client ‑ utils::unexpected_downloaded_file_verifier::tests::compute_expected_state_after_download::when_db_dir_contains_empty_immutable_dir_return_minimal_set
mithril-client ‑ utils::unexpected_downloaded_file_verifier::tests::compute_expected_state_after_download::when_db_dir_empty_return_minimal_set

[dlachaume]

LGTM 👍

[jpraynaud]

LGTM 👍