feat: secure env config, per‑network deployments, expanded DAO test suite, and Python ABI package

[ashutoshpw]

Phase 1 (Completed)

• Replace hardcoded secrets with environment variables and add .env.example.
• Persist deployed contract addresses per network under deployments/.json.
• Improve DX with npm scripts, .nvmrc, and README updates.

Phase 2 (Completed)

• Add comprehensive unit, integration, and e2e tests for DAO flows.
• Provide mocks for external integration testing.

Phase 3 (Ongoing)

• Add a minimal Python package exporting curated ABIs for indexers.
• The PR can be reviewed and subsequent work on this can be added via another PR

Breaking/Behavior Changes

• Scripts no longer mutate config.js with deployed addresses; they write to deployments/.json. Users relying on config.js addresses should switch to the new files or the utils/deployments API
• Environment variables (INFURA_API_KEY, SEPOLIA_PRIVATE_KEY) must be set for networked deploys.

Rationale

• Remove secrets from source control to improve security and align with best practices.
• Make deployments reproducible and auditable per network via versioned JSON.
• Substantially increase test coverage across real‑world DAO workflows and error conditions.
• Provide curated ABIs for downstream indexers/services without shipping full artifacts.
• Enhance developer ergonomics with scripts and clear docs.