feat: add soroban tooling suite - authorization inspector, contract spec viewer, fee estimator, explorer links

[Just-Bamford]

Summary

Implements four new Stellar/Soroban tooling features for the utix platform, addressing critical gaps in transaction analysis, contract inspection, and resource fee transparency.

Closes #123
Closes #122
Closes #120
Closes #124

Features Implemented

1. Soroban Authorization Entry Inspector

Build Soroban Authorization Entry Inspector

Decodes authorization entries from Soroban transaction envelopes and renders the authorization tree showing:

• Who must sign (source account vs. address credentials)
• Which contract functions and sub-invocations are authorized
• Nonce and expiration ledger for address signers
• Identification of unobvious sub-invocations (security risk indicator)

Files: features/soroban-auth-inspector/

• Components for form input, results display, and error handling
• XDR parsing with credential extraction
• Type-safe error codes for all failure paths
• Regression tests covering core functionality

2. Soroban Contract Interface Viewer

Build Soroban Contract Interface Viewer

Fetches deployed contract specifications directly from the blockchain and renders:

• Exported functions with argument and return types
• Custom struct and enum type definitions
• Contract error codes with descriptions
• Direct WASM spec parsing from chain

Files: features/soroban-spec-viewer/

• RPC integration for contract spec retrieval
• XDR-based spec entry extraction from WASM
• Function signature and type rendering
• Network-aware RPC endpoints (mainnet/testnet)

3. Multi-Explorer Link Generator

Build Multi-Explorer Link Generator

Classifies any Stellar identifier and generates direct links on all major explorers:

• Identifiers supported: Accounts (G...), Contracts (C...), Transactions (64 hex), Ledgers (numeric), Assets (CODE:issuer)
• Explorers: Stellar Expert, Stellar Chain, SteExp
• Networks: Mainnet and testnet with correct URL prefixes
• Local-only computation (no external calls)

Files: features/explorer-links/

• Client-side identifier classification logic
• Hardcoded explorer URL patterns for reliability
• Network-aware link generation
• Comprehensive identifier format validation

4. Soroban Resource Fee Estimator

Build Soroban Resource Fee Estimator

Breaks down Soroban transaction resource fees by component:

• CPU instructions with unit pricing
• Memory bytes allocation cost
• Ledger read/write byte costs
• Ledger rent/TTL extension fees
• Identifies dominant cost component
• Comparison of declared vs. estimated fees
• BigInt arithmetic for precision (no floating-point loss)

Files: features/soroban-fee-estimator/

• Envelope XDR parsing for resource declarations
• RPC-based current pricing retrieval (getFeeStats)
• Per-component fee calculation with BigInt
• Sufficient/insufficient fee status determination
• Fallback pricing for offline scenarios

[drips-wave]

@Just-Bamford Great news! 🎉 Based on an automated assessment of this PR, the linked Wave issue(s) no longer count against your application limits.

You can now already apply to more issues while waiting for a review of this PR. Keep up the great work! 🚀

Learn more about application limits