feat: nv28 upgrade mainnet

[LesnyRumcajs]

Summary of changes

Changes introduced in this pull request:

• Set the mainnet NV28 FireHorse network upgrade epoch to 6052800 which corresponds to Wed May 27 02:00:00 PM UTC 2026.

Reference issue to close (if applicable)

Closes

Other information and links

Change checklist

• I have performed a self-review of my own code,
• I have made corresponding changes to the documentation. All new code adheres to the team's documentation standards,
• I have added tests that prove my fix is effective or that my feature works (if possible),
• I have made sure the CHANGELOG is up-to-date. All user-facing changes should be reflected in this document.

Outside contributions

• I have read and agree to the CONTRIBUTING document.
• I have read and agree to the AI Policy document. I understand that failure to comply with the guidelines will lead to rejection of the pull request.

https://filecoinproject.slack.com/archives/C05P37R9KQD/p1778518210802829?thread_ts=1778508150.666689&cid=C05P37R9KQD

Summary by CodeRabbit

• Chores
  • Added support for the FireHorse (NV28) network upgrade scheduled for mainnet at epoch 6052800 (May 27, 2026).
  • Updated actor bundle metadata and state migration configurations for the upcoming upgrade.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Repository UI

Review profile: CHILL

Plan: Pro

Run ID: 6eabfa8a-8307-47ca-a71a-5274d8ec5fd3

📥 Commits

Reviewing files that changed from the base of the PR and between 64bc264 and 6eb136b.

📒 Files selected for processing (5)

• CHANGELOG.md
• build/manifest.json
• src/networks/actors_bundle.rs
• src/networks/mainnet/mod.rs
• src/state_migration/mod.rs

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Walkthrough

This PR activates the NV28 FireHorse network upgrade on mainnet by configuring the activation epoch to block 6052800, registering the v18.0.0 actor bundle with its manifest CIDs, and wiring the state migration to execute at that height.

Changes

NV28 FireHorse Mainnet Activation

Layer / File(s)	Summary
Network upgrade configuration and bundle registration build/manifest.json, src/networks/actors_bundle.rs, src/networks/mainnet/mod.rs	The v18.0.0 actor bundle manifest is registered with all actor CIDs. The HEIGHT_INFOS map is updated to set FireHorse at epoch 6052800 with the v18.0.0 bundle reference, replacing the previous i64::MAX placeholder.
State migration wiring and documentation src/state_migration/mod.rs, CHANGELOG.md	The nv28::run_migration is added to the mainnet migration pipeline at Height::FireHorse. The upgrade epoch and version are documented in the changelog.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~12 minutes

Possibly related PRs

• ChainSafe/forest#6942: Introduces FireHorse height in network height mappings with similar code-level changes to src/networks/mainnet/mod.rs.
• ChainSafe/forest#7003: Updates v18 actor bundle entries and FireHorse HEIGHT_INFOS configuration for a different network (butterflynet).
• ChainSafe/forest#6921: Implements the nv28 module and run_migration function that this PR wires into the migration pipeline.

Suggested labels

Release

Suggested reviewers

• hanabi1224
• akaladarshi

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title 'feat: nv28 upgrade mainnet' directly and clearly summarizes the main change: implementing the NV28 (FireHorse) network upgrade for mainnet with a specific epoch configuration.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 64.17%. Comparing base (64bc264) to head (6eb136b).
✅ All tests successful. No failed tests found.

Additional details and impacted files

Files with missing lines	Coverage Δ
src/networks/actors_bundle.rs	90.35% <100.00%> (+0.04%)	⬆️
src/networks/mainnet/mod.rs	100.00% <100.00%> (ø)
src/state_migration/mod.rs	81.31% <100.00%> (+0.20%)	⬆️

... and 6 files with indirect coverage changes

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