chore(repo): move v1/ → archive/v1/ + add archive/README.md (#430)

The Rust port at v2/ has been the primary codebase since the rename
in #427. The Python implementation at v1/ is no longer the active
target; the only load-bearing path is the deterministic proof bundle
at v1/data/proof/ (per ADR-011 / ADR-028 witness verification).

Move the whole Python tree into archive/v1/ and document the policy
in archive/README.md: no new features, bug fixes only when they affect
a still-load-bearing path (currently just the proof), CI continues to
verify the proof on every push and PR.

Path references updated in 26 files via path-pattern sed (only
matches v1/<known-child> patterns, never bare v1 or API URLs like
/api/v1/). Two double-prefix typos (archive/archive/v1/) caught and
hand-fixed in verify-pipeline.yml and ADR-011.

Validated:
- Python proof verify.py imports cleanly at archive/v1/data/proof/
  (numpy/scipy still required; CI installs requirements-lock.txt
  from archive/v1/ now)
- cargo test --workspace --no-default-features → 1,539 passed,
  0 failed, 8 ignored (unaffected by Python tree relocation)
- ESP32-S3 on COM7 untouched (no firmware paths changed)

After-merge: contributors should re-run any local `python v1/...`
commands as `python archive/v1/...` (CLAUDE.md and CHANGELOG already
updated).

docs/adr/ADR-049-cross-platform-wifi-interface-detection.md

@@ -108,7 +108,7 @@ Remove duplicated platform-detection logic from `ws_server.py` and `install.sh`.
 
 ## Implementation Notes
 
-1. Add `create_collector()` and `BaseCollector.is_available()` to `v1/src/sensing/rssi_collector.py`
+1. Add `create_collector()` and `BaseCollector.is_available()` to `archive/v1/src/sensing/rssi_collector.py`
 2. Refactor `ws_server.py` `_init_collector()` to call `create_collector()`
 3. Update `install.sh` `detect_wifi_hardware()` to use shared detection logic
 4. Add unit tests for each platform path (mock `/proc/net/wireless` presence/absence)