Create airhound-handlers crate (DroneProcessor + ProximityTracker + output pipeline)

[dougborg]

Summary

Create the airhound-handlers crate as a lightweight std crate containing the two genuinely stateful processors and the category-driven output pipeline. This replaces the original 4-handler design.

Crate Structure

crates/airhound-handlers/
  Cargo.toml           # depends on airhound-core
  src/
    lib.rs
    drone.rs           # DroneProcessor (ODID state accumulation)
    proximity.rs       # ProximityTracker (multi-target RSSI tracking)
    pipeline.rs        # Category-driven output routing + dedup
    network_catalog.rs # BSSID dedup map + WiGLE CSV export
    gps.rs             # Shared GPS position
    persistence.rs     # NVS abstraction

Design Philosophy

The rule engine (airhound-core) handles all matching. This crate handles:

1. Stateful processors that need to accumulate state over time:

   • DroneProcessor — merges ODID message types into per-drone records (Implement DroneProcessor (ODID state accumulation) #76)
   • ProximityTracker — tracks RSSI of user-designated target MACs (Implement ProximityTracker (multi-target RSSI tracking) #77)

2. Category-driven output pipeline — simple dedup + routing:

   • Surveillance/Watchlist: MAC dedup with configurable cooldown → alerts
   • Network: BSSID dedup with infinite TTL → catalog + WiGLE CSV export
   • Drone/Proximity: forward to respective processors

3. Shared infrastructure: GPS, NVS persistence

No EventHandler trait — just concrete structs with clear responsibilities.

Requirements

• std crate (HashMap, String, etc.)
• Depends on airhound-core for scan events, filter types, protocol types, proximity math
• cargo test passes on host
• Each component independently testable

Replaces

• Create airhound-handlers crate with EventHandler trait #73 EventHandler trait (closed)
• Implement shared DedupEngine #74 DedupEngine (closed — dedup is now inline in pipeline.rs)
• Implement SurveillanceHandler #75 SurveillanceHandler (closed — rule engine + pipeline dedup)
• Implement WardriverHandler #78 WardriverHandler (closed — network_catalog.rs + pipeline routing)