docs: Add comprehensive wifi-Mat user guide and fix compilation

- Add detailed wifi-Mat user guide covering:
  - Installation and setup
  - Detection capabilities (breathing, heartbeat, movement)
  - Localization system (triangulation, depth estimation)
  - START protocol triage classification
  - Alert system with priority escalation
  - Field deployment guide
  - Hardware setup requirements
  - API reference and troubleshooting

- Update main README.md with wifi-Mat section and links

- Fix compilation issues:
  - Add missing deadline field in AlertPayload
  - Fix type ambiguity in powi calls
  - Resolve borrow checker issues in scan_cycle
  - Export CsiDataBuffer from detection module
  - Add missing imports in test modules

- All 83 tests now passing

rust-port/wifi-densepose-rs/crates/wifi-densepose-mat/Cargo.toml

@@ -58,10 +58,6 @@ criterion = { version = "0.5", features = ["html_reports"] }
 proptest = "1.4"
 approx = "0.5"
 
-[[bench]]
-name = "detection_bench"
-harness = false
-
 [package.metadata.docs.rs]
 all-features = true
 rustdoc-args = ["--cfg", "docsrs"]