Feat/event indexing optimization

[rohans02]

Summary

This PR improves off-chain event filtering efficiency in the TNT protocol by adding indexed parameters to critical event fields.
The change enables faster and more cost-effective querying for analytics, dashboards, and subgraph integrations.

All contracts compile successfully and tests pass. No breaking changes introduced.

Changes

• Added indexed to TNTCreated.tntAddress in Factory.sol
• Added indexed to TokenIssued.tokenId in TNT.sol
• Added indexed to TokenRevoked.tokenId in TNT.sol
• Added new validation test file: EventIndexing.test.js
• Fixed test environment configuration for Hardhat compilation

Impact

• Enables efficient filtered event queries
• Significantly reduces RPC calls for analytics workflows
• Better compatibility with The Graph and similar indexing tools
• Gas overhead: ~+375 gas per event (acceptable trade-off for improved query performance)

Addressed Issues:

Fixes #30

Screenshots/Recordings:

Additional Notes:

Why Test Infrastructure Fixes Are Included

• These changes were necessary to enable Hardhat testing of the event indexing improvements.
• All fixes address pre-existing issues (broken test calls, configuration mismatches).
• None of the fixes affect production contract functionality.

Contract Size Note

• Factory.sol (24.8KB) exceeds Ethereum's 24KB contract size limit.
• This is a separate, pre-existing issue.
• allowUnlimitedContractSize only affects local Hardhat testing.
• Mainnet deployment will still enforce the size limit.
• Recommend opening a separate issue for contract size optimization.

Checklist

• My PR addresses a single issue, fixes a single bug or makes a single improvement.
• My code follows the project's code style and conventions.
• If applicable, I have made corresponding changes or additions to the documentation.
• If applicable, I have made corresponding changes or additions to tests.
• My changes generate no new warnings or errors.
• I have joined the Stability Nexus's Discord server and I will share a link to this PR with the project maintainers there.
• I have read the Contribution Guidelines.
• Once I submit my PR, CodeRabbit AI will automatically review it and I will address CodeRabbit's comments.

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