Research corridor: USDC → BRL (Brazilian Real)

> Written to the standard set by #33 — read that issue first for the expected level of detail. > **This issue is BLOCKED on Track C landing.** Per the agreed sequencing, corridor research should wait until the analysis-depth metrics (#36, #37, #40, #41, #54) are implemented. ## What Research whether a real Stellar-native issuer exists for BRL (Brazilian Real) tokenised as a Stellar asset, and whether Horizon path data exists before any claim is made about liquidity quality. Brazil has had Stellar ecosystem activity (Mercado Bitcoin was a Stellar partner, there have been BRL stablecoin announcements). But announcements are not corridors. This research answers whether the corridor exists on-chain. ## Why it matters Brazil is a large remittance market with significant crypto adoption. If a real BRL issuer exists on Stellar with path data, the corridor is worth measuring. If not, the finding is NO-MARKET — and that is a complete result. ## Which layer **Layer 1 — observable fact.** ## Exactly where the code goes - **Output:** `docs/research-BRL.md` or entry in `docs/corridor-measurements.md` - No code changes ## Where the data comes from 1. Stellar SEP-1 resolution for candidate BRL issuers 2. Horizon account lookup 3. Horizon pathfinding for USDC → BRL 4. SEP-38 endpoint check ## What "unmeasurable" means here If no issuer is found, the finding is "no Stellar-native BRL issuer identified as of [date]." ## Acceptance criteria - [ ] At least one candidate BRL issuer is identified and investigated - [ ] Issuer's `stellar.toml` checked for coherence - [ ] Horizon path data checked - [ ] SEP-38 endpoint checked - [ ] Finding written up with evidence - [ ] If NO-MARKET, stated plainly - [ ] No code changes ## Out of scope Do not change: any Go code, corridor registration, measure workflow, existing corridors. ## How to verify locally ```bash cat docs/research-BRL.md 2>/dev/null ```