feat: relay hardening — restore build, add tests, negentropy adapter

Restores build broken by eeb9d2d (cvm-relay-stability removed deps):
- CMakeLists.txt: restore display.c, font.c, local_relay.c, relay_selector.c, sync_manager.c, axs15231b, qrcode, wisp_relay
- tollgate_main.c: restore display.h, local_relay.h, relay_selector.h, sync_manager.h includes and display calls
- cvm_server.c: kept master's keepalive/timeout/ping-pong fixes

New test infrastructure:
- test-local-relay, test-relay-nip11, test-cvm-roundtrip, test-cvm-mcp, test-cross-board make targets
- test-cvm-roundtrip.mjs: MCP get_config + get_balance via public relay
- test-cross-board.mjs: cross-board payment test
- test-cvm-mcp-relay.mjs: kept from master

New unit tests (35 tests):
- test_display.c: 22 tests for escape_wifi_field
- test_negentropy_adapter.c: 13 tests for negentropy adapter

New modules:
- negentropy_adapter.c/h: NIP-77 adapter skeleton

Docs:
- AGENTS.md: display module docs, new test commands
- RELAY_HARDENING_PLAN.md: hardening checklist
- RELAY_HARDENING_MERGE.md: merge plan and checklist

Cleanup:
- Removed CHECKLIST-CVM-RELAY.md, PLAN-SQUASH-MERGE.md (stale planning docs)
- Removed components/esp-miner submodule

Host unit tests: 63/63 pass

1 files changed, 0 insertions, 35 deletions

diff --git a/CHECKLIST-CVM-RELAY.md b/CHECKLIST-CVM-RELAY.md
deleted file mode 100644
index e7c512d..0000000
--- a/CHECKLIST-CVM-RELAY.md
+++ /dev/null
@@ -1,35 +0,0 @@
-# CVM Relay Stability Checklist
-
-## Pre-flight
-- [x] Create worktree `/home/c03rad0r/esp32-tollgate-cvm-relay`
-- [x] Create branch `feature/cvm-relay-stability` from master
-- [x] Document plan in PLAN-CVM-RELAY.md
-
-## Task 3: Fix Relay Disconnect
-- [x] Modify `cvm_relay_task()` inner loop: 1s TLS read timeout
-- [x] Decouple ping timer from read success
-- [x] Add consecutive-timeout counter for real disconnect detection
-- [x] Handle relay close frames (opcode 0x08)
-- [x] `make test-unit` passes (61/61)
-- [x] Build firmware
-- [x] Lock Board B: `make lock-b PHASE="cvm-relay-stability"`
-- [x] Verify Board B port: `esptool.py --port /dev/ttyACM1 chip_id`
-- [x] Flash Board B via `make flash-b`
-- [x] Monitor serial: confirm WS connected, no disconnect in 120s
-- [ ] Unlock Board B (deferred — may need more testing)
-
-## Task 1: Test get_sessions & get_usage via Relay
-- [x] Write `tests/integration/test-cvm-mcp-relay.mjs`
-- [x] Test: `get_sessions` returns JSON array via relay (0 active sessions)
-- [x] Test: `get_usage` returns metric/price/step fields via relay
-- [x] Both tests PASS on Board B (via `make test-cvm-mcp`)
-
-## Task 2: Test Non-Owner Auth Rejection via Relay
-- [x] Test: non-owner request gets no response (12s wait)
-- [x] Test: owner control request succeeds after non-owner test
-- [x] Both tests PASS on Board B (via `make test-cvm-mcp`)
-
-## Final
-- [x] `make test-unit` — 61 tests pass
-- [x] Commit: 3 commits on feature/cvm-relay-stability
-- [ ] Push to remote (nostr git relay down — will retry later)