refactor: improve loading logs

[glevco]

Motivation

PR #1200 removed sync-v1 indexes, and with that the indexes that require initialization changed. Before, we had indexes interested in blocks, but now we only load the mempool index which is interested in transactions only. This means the Scope iterator skipped a lot of blocks before yielding to the progress log iterator, causing the log to appear stuck for several minutes.

This PR fixes this and also makes some other small improvements on loading logs.

Before:

2026-01-09 18:21:25 [info     ] [hathor.indexes.manager] there are indexes that need initialization indexes_to_init=[<hathor.indexes.memory_mempool_tips_index.MemoryMempoolTipsIndex object at 0x7f0ddd9f6120>]
2026-01-09 18:21:25 [info     ] [hathor.indexes.base_index] loaded info-index              block_count=6196394 first_timestamp=1578075305 latest_timestamp=1767982595 tx_count=1410269

< ~25 minutes with no logs >

2026-01-09 18:47:17 [warning  ] [hathor.indexes.manager] iterator was slow to yield     took_sec=~1551s
2026-01-09 18:47:17 [info     ] [hathor.indexes.manager] loading...  0%                 dt=~1551s height=0 latest_ts=2022-09-07 05:31:04 progress=0.0 remaining_time=? total=0 tx_new=0 tx_rate=0.0
2026-01-09 18:47:47 [info     ] [hathor.indexes.manager] loading...  0%                 dt=~30s height=0 latest_ts=2026-01-07 12:10:48 progress=0.005423797531190747 remaining_time=~289993s total=41257 tx_new=41257 tx_rate=1375.2048410493485

After:

2026-01-09 20:42:27 [info     ] [hathor.indexes.manager] there are indexes that need initialization indexes_to_init=['MemoryMempoolTipsIndex']
2026-01-09 20:42:27 [info     ] [hathor.indexes.base_index] loaded info-index              block_count=6155424 first_timestamp=1578075305 latest_timestamp=1766752000 tx_count=1408999
2026-01-09 20:42:27 [info     ] [hathor.indexes.manager] initializing indexes...
2026-01-09 20:42:27 [info     ] [hathor.indexes.manager] loading...  0%                 dt=<1ms remaining_time=? total=0 tx_new=0 tx_rate=0.0
2026-01-09 20:42:37 [info     ] [hathor.indexes.manager] loading...  2%                 dt=~10s remaining_time=~483s total=153400 tx_new=153400 tx_rate=15339.935631068443

Acceptance Criteria

• Refactor Scope.get_iterator so it yields all txs, not only those that match the scope. It was only used in one place.
• In loading logs:
  • Add names to list of indexes that require initialization.
  • Change progress dt from 30s to 10s.
  • Remove block height and tx timestamp (it only made sense when the load was topological, which it's not anymore).
  • Add initial log on 0%.
  • Remove progress float (this information is already logged as a percentage).

Checklist

• If you are requesting a merge into master, confirm this code is production-ready and can be included in future releases as soon as it gets merged

[github-actions]

Bencher Report

Branch	refactor/improve-loading
Testbed	ubuntu-22.04

🚨 1 Alert

Benchmark	Measure Units	View	Benchmark Result (Result Δ%)	Lower Boundary (Limit %)
sync-v2 (up to 20000 blocks)	Latency minutes (m)	📈 plot 🚷 threshold 🚨 alert (🔔)	1.52 m (-11.64%) Baseline: 1.72 m	1.55 m (101.85%)

Click to view all benchmark results

Benchmark	Latency	Benchmark Result minutes (m) (Result Δ%)	Lower Boundary minutes (m) (Limit %)	Upper Boundary minutes (m) (Limit %)
sync-v2 (up to 20000 blocks)	📈 view plot 🚷 view threshold 🚨 view alert (🔔)	1.52 m (-11.64%) Baseline: 1.72 m	1.55 m (101.85%)	2.06 m (73.64%)

🐰 View full continuous benchmarking report in Bencher

[codecov]

Codecov Report

❌ Patch coverage is 92.30769% with 2 lines in your changes missing coverage. Please review.
✅ Project coverage is 86.30%. Comparing base (b164a87) to head (1901010).
⚠️ Report is 1 commits behind head on master.

Files with missing lines	Patch %	Lines
hathor/indexes/scope.py	66.66%	1 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1549      +/-   ##
==========================================
+ Coverage   86.25%   86.30%   +0.04%     
==========================================
  Files         438      438              
  Lines       33776    33780       +4     
  Branches     5270     5269       -1     
==========================================
+ Hits        29134    29153      +19     
+ Misses       3627     3612      -15     
  Partials     1015     1015              

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