feat: retrieve subgraph url from latest backend config

[gosuto-inzasheru]

claude might or might not have been writing a regex module for me while i was at the coffee machine:

[...]

Perfect! Let me clean up the temporary files and provide a final summary:
Ran tool
Ran tool
Ran tool

✅ Comprehensive Validation Complete!

The TypeScript config loader has been thoroughly tested and validated against all 13 chain configuration files in the Balancer backend repository:

📊 Test Results Summary

✅ 13/13 chain configurations parsed successfully (100% success rate)

Tested Chains:

• arbitrum.ts ✅
• avalanche.ts ✅
• base.ts ✅
• fantom.ts ✅
• fraxtal.ts ✅
• gnosis.ts ✅
• mainnet.ts ✅ (initially failed, now fixed)
• mode.ts ✅
• optimism.ts ✅
• polygon.ts ✅
• sepolia.ts ✅
• sonic.ts ✅
• zkevm.ts ✅

🔍 Specific Value Validation

The loader accurately preserves all tested values including:

• Chain IDs: 42161 (Arbitrum), 1 (Ethereum), 8453 (Base), 137 (Polygon), 250 (Fantom)
• Chain slugs: "arbitrum", "ethereum", "base", "polygon", "fantom"
• Contract addresses: Vault addresses, hook addresses
• RPC URLs: Various provider URLs
• Complex objects: Nested configurations, arrays, bracket notation keys
• Template variables: ${env.THEGRAPH_API_KEY_BALANCER}, ${env.DRPC_API_KEY}, etc.

🛠️ Enhanced Features Added

During testing, the loader was enhanced to handle:

1. BigNumber constructs: BigNumber.from("123") → "123"
2. Object property references: underlyingTokens.USDC → "underlyingTokens.USDC"
3. Complex ternary operators: Multi-line conditional expressions
4. Bracket notation: ['0x123'], ["key"], [key]
5. Template literals: Backtick strings with ${variables}
6. Inline comments: Proper removal without breaking URLs

🎯 Key Capabilities Confirmed

• ✅ No external dependencies (uses only Python standard library)
• ✅ Preserves template variables for runtime substitution
• ✅ Handles complex TypeScript constructs (BigNumber, object refs, ternaries)
• ✅ Robust comment removal (avoids breaking URLs)
• ✅ Accurate type conversion (strings, numbers, objects, arrays)
• ✅ Works with both local files and URLs

The loader successfully converts complex TypeScript configuration files into Python dictionaries while preserving all the essential data structure and template variables needed for runtime configuration.

closes #108

[Xeonus]

RegEx pattern hard to fully validate but test logs from the AI seem to confirm it is working as intended