Fix solidity linting issues across all packages

[RembrandtK]

Status:

• Pending audit to confirm no impact on production deployed bytecode or other need for a full audit.
• Likely to additionally be delayed post-Horizon upgrade completion to avoid intereference.

---

This PR resolves all Solidity linting issues across the monorepo, enabling clean pnpm lint execution.

Additionally:

• Duplicate interface contracts have been removed with interfaces package consistently used.
• Standardised open-ended interface compiler versions to allow wider consumer compatibility with interfaces. Dual-version files use ^0.8.0 since they can't leverage v0.8 only features anyway. V0.8-only files use ^0.8.22 to include custom errors and named mappings.

Summary

• 260 files changed (+5,087 / -1,569 lines)
• ~3,000 NatSpec comments added (@title, @author, @notice, @param, @return, @dev)
• ~220 solhint suppressions with TODO comments for unavoidable violations

Solhint Suppressions Added

Most common suppressed rules (all include TODO comments for future fixes):

• gas-indexed-events (36) - Event parameters without indexed
• use-natspec (36) - Legacy code without documentation
• named-parameters-mapping (25) - Requires Solidity ≥0.8.18
• immutable-vars-naming (19) - Non-UPPER_CASE immutables
• gas-strict-inequalities (15) - Using <= vs <
• gas-custom-errors (7) - Using require (0.7.6 limitation)
• no-inline-assembly (5) - Critical assembly blocks
• const-name-snakecase (3) - Non-UPPER_CASE constants
• Other gas optimizations and formatting rules

Verification

✅ Bytecode comparison (compare script): Only mock/test contracts have functional changes (added indexed to events). All production contracts are functionally identical.

✅ All packages pass pnpm lint with zero errors/warnings

[Copilot]

Pull Request Overview

This PR resolves Solidity linting issues across the monorepo by adding comprehensive NatSpec documentation, implementing solhint suppressions for unavoidable violations, and standardizing interface compiler versions for improved package compatibility.

Key Changes:

• Added ~3,000 NatSpec comments across 260 files
• Implemented ~220 solhint suppressions with TODO comments for future fixes
• Standardized interface pragma versions (^0.8.22 for modern features, ^0.8.0 for dual-version compatibility)
• Removed duplicate interface contracts in favor of centralized interfaces package

Reviewed Changes

Copilot reviewed 263 out of 264 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
packages/token-distribution/package.json	Added @graphprotocol/interfaces dependency
packages/token-distribution/contracts/tests/**/*.sol	Added solhint suppressions and updated imports to use interfaces package
packages/token-distribution/contracts/**/*.sol	Added solhint suppressions and updated imports to use interfaces package
packages/interfaces/contracts/**/*.sol	Standardized pragma versions and added comprehensive NatSpec documentation
packages/interfaces/README.md	Documented compiler version strategy and available type formats
packages/subgraph-service/contracts/**/*.sol	Added NatSpec documentation and updated imports
packages/horizon/contracts/**/*.sol	Added NatSpec documentation and updated imports to use interfaces package
packages/contracts/contracts/**/*.sol	Added solhint suppressions, NatSpec documentation, and updated imports
packages/data-edge/contracts/**/*.sol	Added NatSpec documentation

Files not reviewed (1)

• pnpm-lock.yaml: Language not supported

---

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[Copilot]

Using a statement with just the variable name to silence unused parameter warnings is not a standard Solidity pattern. Consider using a comment or omitting the parameter name instead (e.g., function onSubgraphAllocationUpdate(bytes32 /* subgraphDeploymentID */)).

Suggested change

	function onSubgraphAllocationUpdate(bytes32 subgraphDeploymentID) public pure returns (uint256) {
	subgraphDeploymentID; // silence unused variable warning
	return 0;
	}
	function onSubgraphAllocationUpdate(bytes32 /* subgraphDeploymentID */) public pure returns (uint256) {
	return 0;
	}
	}

[openzeppelin-code]

Fix solidity linting issues across all packages

Generated at commit: d863720f3f03678a68a403f5c319a40a911b7a53

🚨 Report Summary

	Severity Level	Results
Contracts	Critical High Medium Low Note Total	2 5 0 14 38 59
Dependencies	Critical High Medium Low Note Total	0 0 0 0 0 0

---

For more details view the full report in OpenZeppelin Code Inspector

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 84.06%. Comparing base (cd59452) to head (d863720).
⚠️ Report is 4 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1242      +/-   ##
==========================================
+ Coverage   82.84%   84.06%   +1.21%     
==========================================
  Files          47       42       -5     
  Lines        2093     2071      -22     
  Branches      620      615       -5     
==========================================
+ Hits         1734     1741       +7     
+ Misses        359      330      -29     

Flag	Coverage Δ
unittests	84.06% <100.00%> (+1.21%)	⬆️

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