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/edge-modules/README.md

@@ -6,7 +6,7 @@
 
 ```bash
 # Build all modules for ESP32
-cd rust-port/wifi-densepose-rs/crates/wifi-densepose-wasm-edge
+cd v2/crates/wifi-densepose-wasm-edge
 cargo build --target wasm32-unknown-unknown --release
 
 # Run all 632 tests
@@ -144,4 +144,4 @@ Every module talks to the ESP32 through 12 functions:
 - [ADR-039](../adr/ADR-039-esp32-edge-intelligence.md) — Edge processing tiers
 - [ADR-040](../adr/ADR-040-wasm-programmable-sensing.md) — WASM runtime design
 - [ADR-041](../adr/ADR-041-wasm-module-collection.md) — Full module specification
-- [Source code](../../rust-port/wifi-densepose-rs/crates/wifi-densepose-wasm-edge/src/)
+- [Source code](../../v2/crates/wifi-densepose-wasm-edge/src/)