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).

docker/Dockerfile.python

@@ -10,16 +10,16 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
     && rm -rf /var/lib/apt/lists/*
 
 # Install Python dependencies
-COPY v1/requirements-lock.txt /app/requirements.txt
+COPY archive/v1/requirements-lock.txt /app/requirements.txt
 RUN pip install --no-cache-dir -r requirements.txt \
     && pip install --no-cache-dir websockets uvicorn fastapi
 
 # Copy application code
-COPY v1/ /app/v1/
+COPY archive/v1/ /app/v1/
 COPY ui/ /app/ui/
 
 # Copy sensing modules
-COPY v1/src/sensing/ /app/v1/src/sensing/
+COPY archive/v1/src/sensing/ /app/v1/src/sensing/
 
 EXPOSE 8765
 EXPOSE 8080