chore(repo): rename rust-port/wifi-densepose-rs → v2/ (flatten to one level) (#427)

The Rust port lived two directories deep (rust-port/wifi-densepose-rs/)
without any sibling under rust-port/ that warranted the extra level.
Move the whole workspace up to v2/ to match v1/ (Python) at the same
depth and shorten every cd / build command across the repo.

git mv preserves history for all tracked files. 60 files updated for
path references (CI workflows, ADRs, docs, scripts, READMEs, internal
.claude-flow state). Two manual fixes for relative-cd paths in
CLAUDE.md and ADR-043 that became wrong after the depth change
(cd ../.. → cd ..).

Validated:
- cargo check --workspace --no-default-features → clean (after target/
  nuke; the gitignored target/ was carried by the OS rename and had
  hard-coded old paths in build scripts)
- cargo test --workspace --no-default-features → 1,539 passed, 0 failed,
  8 ignored (same totals as pre-rename)
- ESP32-S3 on COM7 → still streaming live CSI (cb #40300, RSSI -64 dBm)

After-merge follow-up: contributors should `rm -rf v2/target` once and
let cargo regenerate from the new path.

docs/ddd/ruvsense-domain-model.md

@@ -16,7 +16,7 @@ This document defines the system using [Domain-Driven Design](https://martinfowl
 | 6 | [Spatial Identity](#6-spatial-identity-context) | Cross-room tracking via environment fingerprints | [ADR-030](../adr/ADR-030-ruvsense-persistent-field-model.md) | `signal/src/ruvsense/cross_room.rs` |
 | 7 | [Edge Intelligence](#7-edge-intelligence-context) | On-device sensing (no server needed) | [ADR-039](../adr/ADR-039-esp32-edge-intelligence.md), [ADR-040](../adr/ADR-040-wasm-programmable-sensing.md) | `firmware/esp32-csi-node/main/edge_processing.c` |
 
-All code paths shown are relative to `rust-port/wifi-densepose-rs/crates/wifi-densepose-` unless otherwise noted.
+All code paths shown are relative to `v2/crates/wifi-densepose-` unless otherwise noted.
 
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