[hardware] Add optional operator-signal fixtures for FlowChain local L1

[FlowmemoryAI]

Objective

Make FlowRouter/Meshtastic-style simulator signals visible to the local L1 package while keeping hardware optional.

Worktree

E:\FlowMemory\flowmemory-hardware on agent/full-l1-hardware.

Acceptance criteria

• Simulator emits deterministic node heartbeat, offline alert, receipt relay, verifier digest relay, bridge alert, and NFC/operator metadata fixtures.
• Fixture validation and negative cases exist.
• Handoff JSON is stable for control-plane ingestion and dashboard display.
• LoRa/Meshtastic remains low-bandwidth control signaling only.
• flowchain:full-smoke can include hardware as optional evidence but does not require physical devices.
• Checks include simulator validation, fixture/schema validation, and git diff --check.

Out of scope

Production hardware, RF certification, field deployment, hardware validator duties, and broadband replacement claims.

[FlowmemoryAI]

Hardware/signals worktree status from E:\FlowMemory\flowmemory-hardware on branch agent/l1-loop-hardware-signals.

Draft PR: #139

Final status: all 8/8 hardware-signals checks are complete after rebasing onto origin/main at 14f378b and force-pushing PR #139 at commit 81ace44.

Hardware acceptance is implemented and locally passing:

node docs/agent-runs/hardware-signals/SCOPE_CHECK.mjs
python hardware/simulator/flowrouter_sim.py --smoke --seed 42
npm run flowchain:hardware:smoke
node docs/agent-runs/hardware-signals/AJV_2020_VALIDATION.mjs
node docs/agent-runs/hardware-signals/NO_SECRET_FIXTURE_SCAN.mjs
node infra/scripts/check-unsafe-claims.mjs
git diff --check
npm run flowchain:product-e2e
npm run flowchain:l1-e2e

Exact npm run flowchain:product-e2e now passes in the unmodified local environment with Slither still on PATH. npm run flowchain:l1-e2e exists after the rebase and passed last. Product/L1 e2e generated broader launch/dashboard/service artifacts during the run; those side effects were restored so the branch keeps only allowed hardware-signals changes.

GitHub CI for PR #139 is passing across repository hygiene, contracts, services/launch core, dashboard, hardware POC, crypto, local devnet, and launch-core acceptance.

Implemented fixture coverage:

• heartbeat
• emergency/offline alert
• compact receipt relay
• verifier report digest relay
• bridge alert
• NFC memory cartridge metadata
• node health
• peer hint

Generated fixture files:

• hardware/fixtures/flowrouter_sample_seed42.json
• fixtures/hardware/flowrouter_local_alpha_seed42.json
• fixtures/hardware/flowrouter_control_plane_handoff_seed42.json
• fixtures/hardware/flowrouter_negative_validation_seed42.json

Negative validation rejects malformed IDs, oversized payloads, stale timestamps, duplicate signal IDs, secret-shaped payloads, required-hardware claims, and missing required handoff collections. Generated hardware fixtures pass the durable no-secret scan, every raw packet type has a matching simulator schema file, and AJV 2020 validates every raw packet, the operator projection, the control-plane handoff, and the negative validation report.

The control-plane handoff is flowmemory.hardware_control_plane_handoff.local_alpha.v0, mode=read-only-optional-merge, with hardwareRequiredForPrivateTestnet=false. Hardware remains optional and cannot block private/local chain startup.

Residual note: explicit npm run contracts:hardening:slither still surfaces the known bridge lockbox audit findings by design. That is a contracts/security audit follow-up and no longer blocks the default product/L1 e2e gate for this hardware PR.