Add alpha-hardening ADRs and issue plan from pre-release audit.

Lock alpha scope, tracker auth, TOPLOC fraud verification, and deferred multi-tracker money-path work; supersede legacy fraud issues with ADR-0018.

Co-authored-by: Cursor <cursoragent@cursor.com>

.scratch/alpha-hardening/issues/03-c5-starting-credit-zero.md

@@ -0,0 +1,38 @@
+Status: ready-for-agent
+
+# 03 — C5 + M1: Starting credit 0, funded-account gate, spend cap
+
+## What to build
+
+Close the free-credit faucet. New API keys start at **0 USDT**; inference requires a real deposit or admin credit. Add a configurable per-request spend cap (M1) to limit runaway charges on compromised keys.
+
+**Code refs:**
+
+- `packages/tracker/meshnet_tracker/billing.py` — `DEFAULT_STARTING_CREDIT = 1.0` (~22), `ensure_client` (~73–85), `has_funds` (~87–88), duplicate credit on charge (~130–138)
+- `packages/tracker/meshnet_tracker/server.py` — billing gate before routing (~1667–1690)
+
+Per ADR-0017 §2 and ADR-0016 §3.
+
+## Test-first
+
+1. Red: new API key gets 1.0 USDT implicit credit — test expects 0 balance until deposit.
+2. Red: first inference without deposit returns 402.
+3. Green: `DEFAULT_STARTING_CREDIT = 0.0`; optional `--max-charge-per-request` config.
+
+## Acceptance criteria
+
+- [ ] `DEFAULT_STARTING_CREDIT` is 0.0; no automatic caller credit on first touch
+- [ ] `has_funds` false for fresh keys; 402 before routing (server.py ~1684)
+- [ ] Admin `credit_client` or bound-wallet deposit still funds accounts
+- [ ] Configurable max charge per request (M1) rejects oversize completions with clear error
+- [ ] Tests: fresh key blocked; after credit/deposit, inference proceeds
+
+## ADR links
+
+- [ADR-0017](../../docs/adr/0017-tracker-authentication-and-authorization.md)
+- [ADR-0016](../../docs/adr/0016-alpha-scope-and-known-limitations.md)
+- [ADR-0015](../../docs/adr/0015-usdt-custodial-settlement.md)
+
+## Blocked by
+
+- `02-a2-unified-auth-boundary.md` (admin credit path secured)