feat: Add AggregationISM to hyperlane-cosmos

[jonas089]

This PR introduces a full implementation of AggregationISM for the hyperlane-cosmos module.

AggregationISM allows composing multiple existing ISMs and enforcing an M-of-N verification policy. Message verification succeeds only if at least threshold child ISMs successfully verify the message.

New ISM type

• AggregationISM with on-chain storage, validation, and routing
• Supports nested aggregation (aggregation ISMs can reference other aggregation ISMs)

Verification logic

• Calls Verify() on each configured child ISM via the core keeper
• Early-exit once the threshold is met (gas-efficient)
• Returns detailed errors when verification fails

State & ownership management

• Owner-controlled updates for:
  • Child module list
  • Threshold
  • Ownership transfer or permanent renouncement
• Ownership checks enforced at the keeper level

Messages & events

• MsgCreateAggregationIsm
• MsgSetAggregationIsmModules
• MsgUpdateAggregationIsmOwner
• Corresponding typed events for all state changes

Validation

• Threshold > 0 and ≤ number of modules
• No duplicate modules
• All referenced ISMs must exist
• Strict ownership and address validation

Tests

• Comprehensive unit and integration tests covering:
  • Success and failure paths
  • Edge cases (invalid configs, missing ISMs)
  • Nested aggregation
  • Gas behavior with large module sets

[mbreithecker]

Thanks for your PR.

Why are you removing all the "Arrange", "Act" and "Assert" comments from the test files?

Can you please make sure that CI passes. You can also run make all locally.

[jonas089]

@mbreithecker I re-added the comments. Removed them because I thought they were not very useful, but I understand that you want to keep them.

Working on CI now.

[Copilot]

Pull request overview

This PR implements AggregationISM for the hyperlane-cosmos module, enabling M-of-N verification by composing multiple existing ISMs. The implementation validates messages when a configurable threshold of child ISMs successfully verify them.

Changes:

• Added AggregationISM type with threshold-based verification and ownership management
• Implemented keeper methods for creating and updating aggregation ISMs
• Added comprehensive validation and testing for edge cases and nested aggregation

Reviewed changes

Copilot reviewed 18 out of 18 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
x/core/01_interchain_security/types/types.pb.go	Generated protobuf code for AggregationISM type definition
x/core/01_interchain_security/types/msg_aggregation.go	Message validation for aggregation ISM operations
x/core/01_interchain_security/types/events.pb.go	Generated event definitions for aggregation ISM lifecycle
x/core/01_interchain_security/types/errors.go	New error types for aggregation validation
x/core/01_interchain_security/types/codec.go	Interface registration for aggregation messages and types
x/core/01_interchain_security/types/aggregation_ism_test.go	Unit tests for validation logic
x/core/01_interchain_security/types/aggregation_ism.go	Core aggregation ISM implementation with validation
x/core/01_interchain_security/keeper/msg_server_test.go	Integration tests for message handlers
x/core/01_interchain_security/keeper/msg_server.go	Keeper methods for aggregation ISM CRUD operations
x/core/01_interchain_security/keeper/keeper.go	Handler registration for aggregation ISM
x/core/01_interchain_security/keeper/genesis.go	Genesis state handling for aggregation ISMs
x/core/01_interchain_security/keeper/aggregation_ism_handler_test.go	Verification logic tests including nested aggregation
x/core/01_interchain_security/keeper/aggregation_ism_handler.go	Aggregation verification handler with early exit optimization
tests/integration/mock.go	Enhanced mock ISM to support pass/fail states
proto/hyperlane/core/interchain_security/v1/types.proto	Protobuf schema for AggregationISM
proto/hyperlane/core/interchain_security/v1/tx.proto	Protobuf definitions for aggregation messages
proto/hyperlane/core/interchain_security/v1/events.proto	Event schemas for aggregation ISM operations

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[Copilot]

The 'bytes' and 'crypto' imports at lines 4 and 10 may no longer be necessary. These imports were likely used in the original code before the refactoring that extracted validateOwnershipTransfer and validateModulesExist. Consider removing unused imports to improve code maintainability.