CLPR-6.2: Ethereum Network Layer Functions

## Story CLPR-6.2: Ethereum Network Layer Functions

**Parent Epic:** CLPR-6: Ethereum On-Chain Service
**Repo:** TBD

### Objective

Implement network layer functions on the Ethereum ClprService: configuration, connection lifecycle, endpoint roster.

### Acceptance Criteria

- **AC-1:** `setLedgerConfiguration(bytes)` — ADMIN_ROLE. Chain ID immutable after first set. Protocol version set by contract.
- **AC-2:** `getLedgerConfiguration()` — No restriction.
- **AC-3:** `registerConnection(bytes32, bytes, bytes, address, bytes)` — Permissionless, payable (if deposit required). ECDSA signature verified. Verifier immutable. `EXTCODEHASH` stored as fingerprint.
- **AC-4:** `updateEndpointRoster(bytes32, bytes)` — Permissionless. Calls `verifyEndpoints`.
- **AC-5:** `pauseConnection` / `resumeConnection` / `closeConnection` — ADMIN_ROLE. Status transitions per cross-platform spec §2.1.1.
- **AC-6:** Connection status: ACTIVE, PAUSED, CLOSED, HALTED. No REGISTERED or CLOSING states.
- **AC-7:** `closeConnection` returns deposit to registrant via CEI pattern.
- **AC-8:** Events: `ConnectionRegistered`, `ConnectionPaused`, `ConnectionResumed`, `ConnectionClosed`.
- **AC-9:** Foundry tests: all functions, status transitions, ECDSA verification, verifier immutability, deposit handling.

### Dependencies

- CLPR-6.1

### Risk

**Medium** — ECDSA recovery, EXTCODEHASH integration, event emission.

Start by reviewing dependency CLPR-6.1 and cross-platform spec §2.1.1, then locate the Ethereum ClprService and its Foundry test area. Cover configuration, connection lifecycle, endpoint roster updates, ECDSA and verifier checks, deposits, status transitions, and required events; done means all acceptance criteria pass.

Written by the indexing model from the issue text.