docs(adr-187): deprecate archive/v1 + honest three-tier model-weights labeling

Add archive/v1/DEPRECATED.md tombstone and a loud deprecation notice atop
archive/v1/README.md: DensePoseHead is architecture-only (random kaiming_normal_
init, zero committed checkpoints under archive/v1/), superseded by the v2/ workspace
and the wifi-densepose 2.x / ruview pip wheel.

Add a 'Model weights: what's real, what's not' three-tier table to README.md and
docs/user-guide.md distinguishing real+validated (presence 82.3%, MM-Fi pose 82.69%
torso-PCK@20, count_v1), real-but-weak (committed pose_v1 at PCK@20=3.0%, runtime
confidence=0 stub, below ADR-079 target), and architecture-only (archive/v1). Caveat
the live single-ESP32 17-keypoint cog advertisement and answer #509 SISO / #1125.

Refs #509, #1125

archive/v1/DEPRECATED.md

@@ -0,0 +1,49 @@
+# ⚠️ DEPRECATED — `archive/v1` is unmaintained and superseded
+
+**Do not build new work on this tree.** `archive/v1` is the original pure-Python
+implementation of WiFi-DensePose. It is kept only as a research archive
+(per [ADR-117 §1.3](../../docs/adr/ADR-117-pip-wifi-densepose-modernization.md)) and
+as the host of one still-live deterministic proof (see "What still lives here" below).
+Everything else in this directory is frozen and receives no fixes, reviews, or support.
+
+Governed by [ADR-187](../../docs/adr/ADR-187-archive-v1-deprecation-honest-labeling.md).
+
+## The one honest fact that trips people up
+
+`archive/v1/src/models/densepose_head.py` defines a `DensePoseHead` neural-network
+architecture (segmentation + UV-regression heads). **It ships no trained weights.** Its
+`_initialize_weights()` uses `kaiming_normal_` **random initialization only** — there is
+no checkpoint-loading path in the class, and there are **zero** `.pth` / `.onnx` /
+`.safetensors` / `.pt` / `.ckpt` / `.bin` files anywhere under `archive/v1/`.
+
+So: the architecture is *defined*, but it is **architecture-only**. Running it produces
+random output, not real pose accuracy. This matches the technical review in
+[#509](https://github.com/ruvnet/RuView/issues/509) — for *this tree*, the "network
+defined, no pre-trained weights" observation is TRUE.
+
+Real, trained, benchmarked weights **do** exist — just not here. They live in the
+maintained `v2/` workspace and on Hugging Face (see next section).
+
+## Use the maintained path instead
+
+| You want… | Go here |
+|-----------|---------|
+| The maintained implementation | The **`v2/` Rust workspace** (repo root `../../v2/`) |
+| A pip install | `pip install ruview` **or** `pip install wifi-densepose` (2.x) — the compiled PyO3 wheel ([ADR-117](../../docs/adr/ADR-117-pip-wifi-densepose-modernization.md)). The `wifi-densepose` **1.x** line is tombstoned on PyPI: `1.99.0` raises an `ImportError` telling you to migrate. |
+| Real trained presence/encoder weights | [`ruvnet/wifi-densepose-pretrained`](https://huggingface.co/ruvnet/wifi-densepose-pretrained) — 82.3% held-out temporal-triplet accuracy |
+| A real 17-keypoint pose model | [`ruvnet/wifi-densepose-mmfi-pose`](https://huggingface.co/ruvnet/wifi-densepose-mmfi-pose) — 82.69% torso-PCK@20 on MM-Fi `random_split` |
+| The honest three-tier weights picture | The "Model weights: what's real, what's not" table in the root [`README.md`](../../README.md) and [`docs/user-guide.md`](../../docs/user-guide.md) |
+
+## What still lives here (intentionally)
+
+Only one thing under `archive/v1/` is still a live, cited signal: the deterministic
+reference-pipeline proof —
+
+```bash
+python archive/v1/data/proof/verify.py   # must print VERDICT: PASS
+```
+
+This is the ADR-028 "Trust Kill Switch": it feeds a fixed reference signal through the
+signal-processing pipeline and checks the SHA-256 of the output against a published hash.
+It is a legitimate reproducibility witness and is **not** deprecated. Everything else in
+this tree is.

archive/v1/README.md

@@ -1,3 +1,19 @@
+> ## ⚠️ DEPRECATED — unmaintained and superseded
+>
+> This tree is the **original pure-Python implementation** and is kept only as a research
+> archive. It receives no fixes, reviews, or support. **Read [`DEPRECATED.md`](DEPRECATED.md) before using anything below.**
+>
+> - Its `DensePoseHead` is **architecture-only with random-initialized weights and ships no
+>   trained checkpoint** — running it produces random output, not real pose accuracy.
+> - The maintained path is the **`v2/` Rust workspace** and the `wifi-densepose 2.x` / `ruview`
+>   pip wheel ([ADR-117](../../docs/adr/ADR-117-pip-wifi-densepose-modernization.md)). The
+>   `wifi-densepose` 1.x line is tombstoned on PyPI (1.99.0 raises `ImportError`).
+> - Real trained weights live elsewhere: [`ruvnet/wifi-densepose-pretrained`](https://huggingface.co/ruvnet/wifi-densepose-pretrained)
+>   (presence, 82.3%) and [`ruvnet/wifi-densepose-mmfi-pose`](https://huggingface.co/ruvnet/wifi-densepose-mmfi-pose)
+>   (17-keypoint pose, 82.69% torso-PCK@20).
+> - The only still-live artifact here is the deterministic proof `data/proof/verify.py`
+>   (ADR-028), which stays. See [ADR-187](../../docs/adr/ADR-187-archive-v1-deprecation-honest-labeling.md).
+
 # WiFi-DensePose v1 (Python Implementation)
 
 This directory contains the original Python implementation of WiFi-DensePose.