diff --git a/.github/workflows/firmware-ci.yml b/.github/workflows/firmware-ci.yml
index 43ac4031..57730feb 100644
--- a/.github/workflows/firmware-ci.yml
+++ b/.github/workflows/firmware-ci.yml
@@ -52,14 +52,16 @@ jobs:
             target: esp32s3
             sdkconfig: sdkconfig.defaults
             partition_table_name: partitions_display.csv
-            size_limit_kb: 1100
+            size_warn_kb: 1100
+            size_limit_kb: 1152
             artifact_app: esp32-csi-node.bin
             artifact_pt: partition-table.bin
           - variant: 4mb
             target: esp32s3
             sdkconfig: sdkconfig.defaults.4mb
             partition_table_name: partitions_4mb.csv
-            size_limit_kb: 1100
+            size_warn_kb: 1100
+            size_limit_kb: 1152
             artifact_app: esp32-csi-node-4mb.bin
             artifact_pt: partition-table-4mb.bin
           # ADR-110: ESP32-C6 research target (Wi-Fi 6 / 802.15.4 / TWT / LP-core)
@@ -67,7 +69,8 @@ jobs:
             target: esp32c6
             sdkconfig: sdkconfig.defaults
             partition_table_name: partitions_4mb.csv
-            size_limit_kb: 1100
+            size_warn_kb: 1100
+            size_limit_kb: 1152
             artifact_app: esp32-csi-node-c6.bin
             artifact_pt: partition-table-c6.bin
 
@@ -96,18 +99,23 @@ jobs:
           make test_adr110
           ./test_adr110
 
-      - name: Verify binary size (< ${{ matrix.size_limit_kb }} KB gate)
+      - name: Verify binary size budget
         working-directory: firmware/esp32-csi-node
         run: |
           BIN=build/esp32-csi-node.bin
           SIZE=$(stat -c%s "$BIN")
           MAX=$((${{ matrix.size_limit_kb }} * 1024))
+          WARN=$((${{ matrix.size_warn_kb }} * 1024))
           echo "Binary size: $SIZE bytes ($(( SIZE / 1024 )) KB)"
+          echo "Warning at:  $WARN bytes (${{ matrix.size_warn_kb }} KB)"
           echo "Size limit:  $MAX bytes (${{ matrix.size_limit_kb }} KB)"
           if [ "$SIZE" -gt "$MAX" ]; then
             echo "::error::Firmware binary exceeds ${{ matrix.size_limit_kb }} KB size gate ($SIZE > $MAX)"
             exit 1
           fi
+          if [ "$SIZE" -gt "$WARN" ]; then
+            echo "::warning::Firmware binary exceeds the ${{ matrix.size_warn_kb }} KB soft budget ($SIZE > $WARN); hard limit is ${{ matrix.size_limit_kb }} KB"
+          fi
           echo "Binary size OK: $SIZE <= $MAX"
 
       - name: Verify flash image integrity
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 9fd3bffa..c44ddb5b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -11,10 +11,13 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - **`@ruvnet/rvagent` startup optimization — stdio time-to-first-response ~242 ms → ~189 ms (−22%; MEASURED, median of repeated `initialize` round-trips against `dist/index.js`, this container, reproduce with a piped-stdin timer).** Two changes: (1) `./http-transport.js` is now imported **lazily** inside the `RVAGENT_HTTP_PORT` branch — it chain-loads the MCP SDK's `streamableHttp` module (~48 ms MEASURED via per-module `import()` timing), which the default stdio path never uses; (2) the advertised JSON Schemas generated from the Zod sources are memoized per tool instead of re-walking the Zod tree on every `tools/list` (matters under the session-per-server HTTP model where each session lists tools). No behavior change: 99/99 jest tests, HTTP session flow re-smoke-tested through the lazy path. The `@ruvnet/ruview` harness CLI was profiled too and left alone — 50 ms vs the ~29 ms bare `node -e ''` floor on the same box (MEASURED), i.e. already near the interpreter floor with zero dependencies.
 
 ### Fixed
+- **FastAPI health/metrics endpoints event-loop starvation.** Calling `psutil.cpu_percent(interval=1)` blocked the single-threaded async event loop for 1.0 second on every health check or metrics collection tick, stalling all incoming requests and WebSocket operations. Fixed by changing `cpu_percent` to use non-blocking `interval=None` and offloading all blocking OS metrics gathering to background thread pools via `asyncio.to_thread`. Verified event loop responsiveness via concurrency regression tests.
 - **EngineBridge now honors `WDP_GUARD_INTERVAL_US`/`WDP_SOFT_GUARD_US`/`WDP_TDM_SLOTS`+`WDP_TDM_SLOT_US`** (#1309, PR #1312, @erichkusuki). The governed trust path previously built its multistatic fuser from a hardcoded `MultistaticConfig::default()` (60 ms guard), so multi-node deployments with WiFi/ESP-NOW time sync (10–150 ms drift) failed every governed cycle regardless of configuration — while the startup log claimed the override took effect. New `StreamingEngine::set_multistatic_config()`; `EngineBridge::new()` takes an `Option<MultistaticConfig>` threaded from the same env-derived config as `AppState.multistatic_fuser`. Hardware-verified on a live 2-node ESP32-S3 setup (90 s window, 0 fusion errors; previously every cycle failed).
 - **`/api/v1/stream/pose` WebSocket reachable with `RUVIEW_API_TOKEN` set + dashboard bearer-token field** (#1310, PR #1313, @erichkusuki). Browsers cannot attach an `Authorization` header to a WS upgrade, so the Live Demo pose stream always failed when auth was on; the path is now on a narrow exact-match exemption list (mirrors `/ws/sensing`), with a regression test pinning that the exemption doesn't leak to other `/api/v1/*` paths. The QuickSettings panel gains an "API Access" field storing the bearer token in `localStorage`; the token is applied at `api.service.js` module load so the very first request carries it.
 - **Display-less DevKitC-1 boards: `sdkconfig.defaults.devkitc` build overlay** (#1308, PR #1311, @erichkusuki). The ADR-045 runtime display probe false-positives on stock ESP32-S3-DevKitC-1 (floating QSPI pins), which silently skipped the RuView#893 MGMT+DATA CSI upgrade and collapsed CSI yield to 0 pps. The overlay compiles display support out (`has_display` constant-false). Also fixes stale `espressif/idf:v5.2` README references to v5.4 (source requires `esp_driver_uart`, IDF ≥5.3). Hardware-verified on 2× DevKitC-1-N16R8 (0 → 40–45 pps).
 - **ADR-263/264/265 implemented — the RuView npm surface fixed end-to-end (`@ruvnet/ruview@0.2.0`, `@ruvnet/rvagent@0.2.0`, `@ruv/ruview-cli`).** Harness (ADR-263 O1–O9): `claim-check` now **fails closed** on empty input (CLI exit 2 + `empty_text` tool error); the MCP stdio server dispatches `tools/call` asynchronously over promise-based `spawn` — `ping` answers while a long `verify`/`calibrate` runs (pinned by a new e2e test that runs a 3 s fake proof and asserts sub-second ping); the two `optionalDependencies` are gone so a cold `npx` installs exactly 1 package (MEASURED: was 4 packages / 620 kB / 71 files, `npm i` in a clean prefix); child output is captured as bounded rolling tails (no more 1 MiB `maxBuffer` kills); `node_monitor` passes the port via `sys.argv` instead of splicing it into `python -c` source; the MCP `serverInfo.version` reads package.json; `.claude/skills/*/SKILL.md` are generated from `skills/*.md` by a `prepack` sync script (byte-equality pinned by test); `which()` is a memoized dep-free PATH scan; tools are underscore-canonical (`ruview_claim_check`, …) with the dotted names accepted as call-time aliases, plus `resources/list`/`prompts/list` stubs; the guardrail's `METRIC_TERMS` matching is precision-fixed (word-boundary `map`/`f1`/`auc`/`iou`, code-span + label scrubbing, quantitative-claims-only) — ADR-263/264/265 and both package READMEs now PASS `claim-check` while real untagged claims still flag. 30/30 tests (MEASURED, `node --test`). rvagent (ADR-264 O1–O9): `exports` fixed (types-first, the never-built `dist/index.cjs` `require` target removed — verified broken in the published 0.1.0 tarball); tarball is map-free (127,704 B unpacked / 46 files / 0 maps — MEASURED, `npm pack --dry-run`, down from 188 kB with 44 maps); the Streamable HTTP transport is **actually wired** behind `RVAGENT_HTTP_PORT` with one transport + one MCP server per session (`mcp-session-id` routing), a 1 MiB body cap (413), and a port-aware localhost origin gate — the "dual-transport" description is now true; tools renamed to underscore-canonical with dotted router aliases; ONE Zod validation gate per call with the advertised JSON Schema generated from the same Zod source (`zod-to-json-schema`); `train_count` closes its log fds (was leaking 2/job) and persists job records to `<jobsDir>/<id>.json` so `job_status` survives restarts, with bounded log-tail reads; `detectCogBinary` actually probes its candidate paths; version reads package.json; `@types/express` dropped, `@types/jest` aligned to jest 29; README rewritten to match reality (no phantom `stdio`/`http`/`policy grant` subcommands; unimplemented ADR-124 catalog tools labeled roadmap). 99/99 jest tests (MEASURED); stdio handshake + HTTP session flow + 403/400/404/413 gates smoke-tested live. CLI: bin renamed `ruview-cli` (the `ruview` bin belongs to `@ruvnet/ruview`, ADR-265 D4), version single-sourced. Distribution (ADR-265 D1–D4): new `npm-packages.yml` (3-package × Node 20/22 matrix: tests, version-literal grep gate, pack-content/size gate, tarball-install smoke test incl. the fail-closed claim-check and an ESM-import probe that would have caught the broken `require` export, README claim-check) and `ruview-npm-release.yml` (publish from CI only, `npm publish --provenance`); `ci.yml` NODE_VERSION 18→20.
+- **Empty-room field-model calibration collected nothing on real HT40 nodes — raw 128-wide frames rejected by the 56-tone model (follow-up to the deadlock fix below).** Once the status-gate deadlock was fixed, `maybe_feed_calibration` reached `feed_calibration`, but a real ESP32 HT40 node streams 128-wide amplitude vectors while the single-link `FieldModel` is the canonical 56-tone grid — so `LinkStats::update` returned `DimensionMismatch`, `feed_calibration` bubbled the error, and `maybe_feed_calibration` swallowed it at `debug` level. Net effect: `frame_count` stayed pinned at 0 on live hardware even though presence/motion/vitals (which read the global history) worked fine. Fixed by resampling each frame onto the model's canonical 56-tone grid via `HardwareNormalizer::resample_to_canonical` before feeding — the same length-only canonicalization the multistatic fusion path uses (#1170). Pinned by `field_bridge::maybe_feed_calibration_resamples_wide_frames_and_accumulates` (128-wide frame → Collecting + count 1; fails on old code). Verified live on the ESP32-S3 deployment.
+- **Empty-room field-model calibration could never start — `/api/v1/calibration/*` was a dead endpoint (frame count pinned at 0).** `POST /calibration/start` creates the `FieldModel` in `Uncalibrated`, but the per-frame server feed `field_bridge::maybe_feed_calibration` only fed observations while the model was **already** `Collecting` — and the *only* thing that sets `Collecting` is `feed_calibration` itself (on its first fed frame). The two gates deadlocked: nothing ever fed the first frame, so `calibration_frame_count` stayed 0, `status` never left `Uncalibrated`, and the SVD room eigenstructure (eigenvalue-based person counting / localization) could never calibrate — observed live as `{"status":"Uncalibrated","frame_count":0}` never advancing on a streaming ESP32 node. Fixed the guard to feed while `Uncalibrated | Collecting` so the first frame flips the model to `Collecting` and the count advances. Also made `calibration_stop` return a structured `{success:false, frame_count, frames_needed}` (with a new `FieldModel::min_calibration_frames()` accessor) instead of an opaque 500 when finalized before enough empty-room frames accumulate. Pinned by `field_bridge::maybe_feed_calibration_advances_uncalibrated_to_collecting` (asserts `Uncalibrated → Collecting` + count 0 → 1 → 2; fails on old code). Presence/motion/vitals were unaffected — they use the separate auto rolling baseline, not the field model.
 - **Multistatic fusion never ran on a mixed-mode ESP32 mesh — live bridge fed raw, un-canonicalized per-node CSI to the fuser (#1170).** `node_frame_from_state` (`multistatic_bridge.rs`) wrapped each node's **raw** amplitude vector (HT20 ≈ 64 bins, HT40 ≈ 128/192) into a struct *named* `CanonicalCsiFrame` without ever resampling, so `MultistaticFuser::fuse` tripped `DimensionMismatch` on every cycle, silently fell back to per-node sum/dedup, and spun `total_engine_errors` unbounded. Added `HardwareNormalizer::resample_to_canonical` (resample-only, **no z-score** — preserves the amplitude scale the person-score's `variance/mean²` relies on) and run every node frame through it onto the canonical 56-tone grid before fusion. Heterogeneous meshes now fuse instead of erroring. Pinned by `heterogeneous_node_counts_canonicalize_and_fuse` (mixed 64/192 → fuses), `resample_to_canonical_is_length_only_no_zscore`, and an updated `test_node_frame_conversion`; the pre-existing `engine_bridge::observe_cycle_counts_engine_errors` was retargeted to force a `TimestampMismatch` (its old 56-vs-30 setup now canonicalizes cleanly). `wifi-densepose-signal` 501 / `wifi-densepose-sensing-server` 677 tests, 0 failed.
 - **`csi_fps_ema` reported the CSI frame rate 40–840× too high under bursty UDP delivery (#1180).** `update_csi_fps_ema` only rejected deltas `≤ 0` or `≥ 1 s`, so a 36 µs intra-burst arrival delta yielded `1/dt ≈ 27 kHz` straight into the EMA — the metric measured server arrival jitter, not the node's ~40 fps production rate. Added a `MIN_PLAUSIBLE_CSI_DT_SEC = 0.005` floor (derived from the firmware's 50 fps `CSI_MIN_SEND_INTERVAL_US` ceiling, ×4 slack) and made `observe_csi_frame_arrival` keep its anchor across sub-floor bursts so the next genuine inter-frame gap measures true cadence. Pinned by `subms_burst_delta_rejected`, `burst_interleaved_with_nominal_stays_in_band`, and `observe_csi_frame_arrival_ignores_subms_bursts`.
 - **`stream_sender` ENOMEM backoff starved low-rate control packets under a weak uplink (#1183, follow-up to #1135/#1159).** The global `s_backoff_until_us` gate (triggered by the 50 Hz CSI flood at weak RSSI) also suppressed the ≤48 B, ≤1 Hz `feature_state` / mesh `HEALTH` / sync packets that contribute negligible buffer pressure, so telemetry failed essentially every cycle. Added `stream_sender_send_priority()` — bypasses the backoff gate, reports ENOMEM quietly, and never extends/resets the global streak — and routed `feature_state`, HEALTH/anomaly (`rv_mesh_send`), and sync packets through it. Also fixed the misleading `"HEALTH sent"` log that printed unconditionally even when `rv_mesh_send` returned `ESP_FAIL` (now prints `sent`/`FAILED` from the actual return). Firmware builds clean (ESP-IDF v5.4).
diff --git a/CLAUDE.md b/CLAUDE.md
index 262884dc..06461a8e 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -93,6 +93,8 @@ All 5 ruvector crates integrated in workspace:
 
 **Not supported:** ESP32 (original), ESP32-C3 — single-core, can't run CSI DSP pipeline.
 
+**⚠️ Compact boards (SuperMini, ESP32-S3-Zero, other coin-sized clones) run hot:** the firmware keeps the WiFi radio on continuously (`WIFI_PS_NONE`) and runs a full DSP pipeline (`edge_tier=2`), which is sustained high current draw. Full-size dev boards handle this fine; coin-sized clones with minimal PCB copper and budget regulators can run uncomfortably hot and, per at least one field report, have failed to power on again after a hot session. Give them airflow and check by touch during the first few minutes. See `firmware/esp32-csi-node/README.md` for details.
+
 ### Build & Test Commands (this repo)
 ```bash
 # Rust — full workspace tests (1,031+ tests, ~2 min)
diff --git a/archive/v1/src/api/routers/health.py b/archive/v1/src/api/routers/health.py
index fdc321eb..013fa35c 100644
--- a/archive/v1/src/api/routers/health.py
+++ b/archive/v1/src/api/routers/health.py
@@ -2,6 +2,7 @@
 Health check API endpoints
 """
 
+import asyncio
 import logging
 import psutil
 from typing import Dict, Any, Optional
@@ -168,7 +169,7 @@ async def health_check(request: Request):
             overall_status = "degraded"
         
         # Get system metrics
-        system_metrics = get_system_metrics()
+        system_metrics = await asyncio.to_thread(get_system_metrics)
         
         uptime_seconds = (datetime.now() - _APP_START_TIME).total_seconds()
         
@@ -263,11 +264,12 @@ async def get_health_metrics(
 ):
     """Get detailed system metrics."""
     try:
-        metrics = get_system_metrics()
+        metrics = await asyncio.to_thread(get_system_metrics)
         
         # Add additional metrics if authenticated
         if current_user:
-            metrics.update(get_detailed_metrics())
+            detailed = await asyncio.to_thread(get_detailed_metrics)
+            metrics.update(detailed)
         
         return {
             "timestamp": datetime.utcnow().isoformat(),
@@ -300,7 +302,7 @@ def get_system_metrics() -> Dict[str, Any]:
     """Get basic system metrics."""
     try:
         # CPU metrics
-        cpu_percent = psutil.cpu_percent(interval=1)
+        cpu_percent = psutil.cpu_percent(interval=None)
         cpu_count = psutil.cpu_count()
         
         # Memory metrics
diff --git a/archive/v1/src/services/metrics.py b/archive/v1/src/services/metrics.py
index 6799ec7d..52b57c03 100644
--- a/archive/v1/src/services/metrics.py
+++ b/archive/v1/src/services/metrics.py
@@ -180,21 +180,24 @@ class MetricsService:
     async def _collect_system_metrics(self):
         """Collect system-level metrics."""
         try:
-            # CPU usage
-            cpu_percent = psutil.cpu_percent(interval=1)
+            # Query OS metrics in a background thread to prevent blocking the event loop
+            def gather_metrics():
+                return (
+                    psutil.cpu_percent(interval=None),
+                    psutil.virtual_memory().percent,
+                    psutil.disk_usage('/'),
+                    psutil.net_io_counters()
+                )
+            
+            cpu_percent, mem_percent, disk, network = await asyncio.to_thread(gather_metrics)
+            
+            # Record metrics on the main loop
             self._metrics["system_cpu_usage"].add_point(cpu_percent)
+            self._metrics["system_memory_usage"].add_point(mem_percent)
             
-            # Memory usage
-            memory = psutil.virtual_memory()
-            self._metrics["system_memory_usage"].add_point(memory.percent)
-            
-            # Disk usage
-            disk = psutil.disk_usage('/')
             disk_percent = (disk.used / disk.total) * 100
             self._metrics["system_disk_usage"].add_point(disk_percent)
             
-            # Network I/O
-            network = psutil.net_io_counters()
             self._metrics["system_network_bytes_sent"].add_point(network.bytes_sent)
             self._metrics["system_network_bytes_recv"].add_point(network.bytes_recv)
             
diff --git a/archive/v1/tests/unit/test_health_concurrency.py b/archive/v1/tests/unit/test_health_concurrency.py
new file mode 100644
index 00000000..438356ae
--- /dev/null
+++ b/archive/v1/tests/unit/test_health_concurrency.py
@@ -0,0 +1,59 @@
+import asyncio
+import time
+import os
+import sys
+
+import pytest
+
+# Add project root and archive/v1 to sys.path so we can import src modules
+sys.path.append(os.path.abspath(os.path.join(os.path.dirname(__file__), "../../../../")))
+sys.path.append(os.path.abspath(os.path.join(os.path.dirname(__file__), "../../")))
+
+from archive.v1.src.api.routers.health import get_system_metrics
+
+async def ticker():
+    """Asynchronous background ticker to measure event loop latency/freezes."""
+    ticks = []
+    for _ in range(15):
+        ticks.append(time.time())
+        await asyncio.sleep(0.1)
+    return ticks
+
+async def run_test():
+    print("Starting concurrency verification test...")
+    
+    # Start the ticker background task
+    ticker_task = asyncio.create_task(ticker())
+    
+    # Let ticker run for a few ticks
+    await asyncio.sleep(0.3)
+    
+    print("Calling get_system_metrics offloaded to background thread...")
+    start_time = time.time()
+    
+    # Query system metrics using to_thread (simulating FastAPI request)
+    metrics = await asyncio.to_thread(get_system_metrics)
+    
+    duration = time.time() - start_time
+    print(f"get_system_metrics took: {duration:.4f}s")
+    
+    # Wait for the ticker to complete
+    ticks = await ticker_task
+    
+    # Calculate gaps between consecutive ticks to check for event loop freezes
+    gaps = [ticks[i+1] - ticks[i] for i in range(len(ticks)-1)]
+    max_gap = max(gaps)
+    
+    print(f"All tick gaps: {[round(g, 3) for g in gaps]}")
+    print(f"Max event loop freeze: {max_gap:.4f}s")
+    
+    # In pre-fix code, psutil.cpu_percent(interval=1) blocks for 1.0s,
+    # causing a gap of >1.0s. With our fix, it should be close to 0.1s.
+    return max_gap, duration
+
+@pytest.mark.asyncio
+async def test_get_system_metrics_does_not_starve_event_loop():
+    max_gap, duration = await run_test()
+    # ticker sleeps 0.1s; allow slack for CI, but we should not see ~1s gaps
+    assert max_gap < 0.6
+    assert duration < 0.6
diff --git a/docs/user-guide.md b/docs/user-guide.md
index cf71df73..d9542a6e 100644
--- a/docs/user-guide.md
+++ b/docs/user-guide.md
@@ -1861,6 +1861,23 @@ node scripts/eval-wiflow.js \
   --data data/paired/*.jsonl
 ```
 
+> **Model format boundary:** `train-wiflow-supervised.js` produces the
+> JavaScript WiFlow model `wiflow-v1.json`. There is currently no supported
+> command that converts that JSON model into the sensing server's binary RVF
+> container, and renaming the file to `.rvf` does not convert it. Use the JSON
+> model with the JavaScript evaluation/inference tools. To train a model that
+> the Rust sensing server can load, use its native training path, which writes
+> RVF directly:
+>
+> ```bash
+> cargo run -p wifi-densepose-sensing-server --release -- \
+>   --train --dataset data/mmfi --dataset-type mmfi \
+>   --epochs 100 --save-rvf models/room-model.rvf
+> ```
+>
+> The camera+CSI paired JSONL workflow and the native RVF trainer are separate
+> pipelines today. A JSON-to-RVF exporter is future work.
+
 **Evaluation protocol matters.** Use `eval-wiflow.js` (torso-normalized
 PCK@20, the metric comparable to published WiFi-pose results) on a temporal
 hold-out, and sanity-check that predictions actually vary across frames
diff --git a/firmware/esp32-csi-node/CMakeLists.txt b/firmware/esp32-csi-node/CMakeLists.txt
index 73efbf9f..1658cd32 100644
--- a/firmware/esp32-csi-node/CMakeLists.txt
+++ b/firmware/esp32-csi-node/CMakeLists.txt
@@ -1,5 +1,5 @@
 # ESP32 CSI Node Firmware (ADR-018)
-# Requires ESP-IDF v5.2+
+# Requires ESP-IDF v5.4+
 cmake_minimum_required(VERSION 3.16)
 
 set(EXTRA_COMPONENT_DIRS "")
diff --git a/firmware/esp32-csi-node/README.md b/firmware/esp32-csi-node/README.md
index 9be2509d..b2dda8ab 100644
--- a/firmware/esp32-csi-node/README.md
+++ b/firmware/esp32-csi-node/README.md
@@ -113,6 +113,8 @@ curl http://<ESP32_IP>:8032/wasm/list
 
 > **Tip:** A single node provides presence and vital signs along its line of sight. Multiple nodes (3-6) create a multistatic mesh that resolves 3D pose with <30 mm jitter and zero identity swaps.
 
+> **⚠️ Thermal warning — compact boards (ESP32-S3-Zero, SuperMini, other coin-sized clones):** This firmware runs the WiFi radio with modem sleep disabled (`WIFI_PS_NONE`, required for continuous CSI capture) plus a full edge-processing DSP pipeline on Core 1 (`edge_tier=2`) plus, on ADR-183 builds, a continuous 40 Hz onboard LED driver. That's sustained high current draw with no duty-cycling. Full-size dev boards (DevKitC-1, XIAO) have more copper pour and thermal mass around the regulator and tolerate this fine. Coin-sized clones with minimal PCB area and budget regulators may run hot to the touch during normal operation, and in at least one field report, boards that ran hot during a session failed to power on afterward (regulator damage suspected — see issue tracker). Give these boards airflow, don't stack or enclose them, and check them by touch during the first several minutes of a new deployment. If a board is uncomfortably hot (not just warm), power it down and let it cool before continuing.
+
 ---
 
 ## Firmware Architecture
diff --git a/firmware/esp32-csi-node/main/main.c b/firmware/esp32-csi-node/main/main.c
index 67973cee..6627bbbb 100644
--- a/firmware/esp32-csi-node/main/main.c
+++ b/firmware/esp32-csi-node/main/main.c
@@ -67,6 +67,8 @@ static void event_handler(void *arg, esp_event_base_t event_base,
     if (event_base == WIFI_EVENT && event_id == WIFI_EVENT_STA_START) {
         esp_wifi_connect();
     } else if (event_base == WIFI_EVENT && event_id == WIFI_EVENT_STA_DISCONNECTED) {
+        wifi_event_sta_disconnected_t *disc = (wifi_event_sta_disconnected_t *)event_data;
+        ESP_LOGW(TAG, "WiFi disconnected, reason=%d rssi=%d", disc->reason, disc->rssi);
         if (s_retry_num < MAX_RETRY) {
             esp_wifi_connect();
             s_retry_num++;
@@ -102,7 +104,10 @@ static void wifi_init_sta(void)
 
     wifi_config_t wifi_config = {
         .sta = {
-            .threshold.authmode = WIFI_AUTH_WPA2_PSK,
+            /* WPA_PSK (not WPA2_PSK) so routers running WPA/WPA2-mixed
+             * compatibility mode aren't rejected with
+             * WIFI_REASON_NO_AP_FOUND_IN_AUTHMODE_THRESHOLD (#1050). */
+            .threshold.authmode = WIFI_AUTH_WPA_PSK,
         },
     };
 
diff --git a/firmware/esp32-csi-node/version.txt b/firmware/esp32-csi-node/version.txt
index faef31a4..b60d7196 100644
--- a/firmware/esp32-csi-node/version.txt
+++ b/firmware/esp32-csi-node/version.txt
@@ -1 +1 @@
-0.7.0
+0.8.4
diff --git a/plugins/ruview/skills/ruview-hardware-setup/SKILL.md b/plugins/ruview/skills/ruview-hardware-setup/SKILL.md
index dd5bf319..8bf134f2 100644
--- a/plugins/ruview/skills/ruview-hardware-setup/SKILL.md
+++ b/plugins/ruview/skills/ruview-hardware-setup/SKILL.md
@@ -18,6 +18,8 @@ Bring a RuView sensing node online: build firmware → flash → provision WiFi
 
 **Not supported:** original ESP32, ESP32-C3 (single-core).
 
+**⚠️ Ask about board form factor before flashing.** If the user's board is a coin-sized clone (ESP32-S3-Zero, SuperMini, or similar — not a full DevKitC/XIAO-style board with a real USB connector and visible regulator), warn them before they walk away from it: this firmware runs the WiFi radio continuously (`WIFI_PS_NONE`) plus a full DSP pipeline (`edge_tier=2`), which is sustained high current draw that full-size dev boards handle fine but tiny clones with minimal copper/budget regulators may not. At least one field report: boards ran hot during a normal session and failed to power on again afterward (regulator damage suspected). Tell them to give the board airflow (don't stack/enclose it) and check it by touch during the first several minutes of any new deployment.
+
 ## 1. Build firmware (Windows — Python subprocess, NOT bash directly)
 
 ESP-IDF v5.4 does not support MSYS2/Git Bash. Use the Espressif Python venv as a subprocess with `MSYSTEM*` env vars stripped. The proven command lives in `CLAUDE.local.md` — reproduce it:
diff --git a/python/bench/test_bench_vitals.py b/python/bench/test_bench_vitals.py
index 06bccb62..3e018a2d 100644
--- a/python/bench/test_bench_vitals.py
+++ b/python/bench/test_bench_vitals.py
@@ -57,12 +57,12 @@ def test_heart_rate_extract_per_frame_cost(benchmark) -> None:
     hr = HeartRateExtractor.esp32_default()
     rng = Random(43)
     for i in range(1500):
-        residuals, weights = _synth_frame(56, 100.0, i / 100.0, 1.2, rng)
-        hr.extract(residuals=residuals, weights=weights)
+        residuals, phases = _synth_frame(56, 100.0, i / 100.0, 1.2, rng)
+        hr.extract(residuals=residuals, phases=phases)
 
     def _one_frame():
-        residuals, weights = _synth_frame(56, 100.0, 16.0, 1.2, rng)
-        return hr.extract(residuals=residuals, weights=weights)
+        residuals, phases = _synth_frame(56, 100.0, 16.0, 1.2, rng)
+        return hr.extract(residuals=residuals, phases=phases)
 
     benchmark(_one_frame)
 
diff --git a/python/src/bindings/vitals.rs b/python/src/bindings/vitals.rs
index ce9613b7..c30844a0 100644
--- a/python/src/bindings/vitals.rs
+++ b/python/src/bindings/vitals.rs
@@ -242,7 +242,22 @@ impl PyBreathingExtractor {
 // ─── HeartRateExtractor ──────────────────────────────────────────────
 
 /// Extracts heart rate (40–120 BPM) from per-subcarrier amplitude
-/// residuals via 0.8–2.0 Hz bandpass + autocorrelation peak detection.
+/// residuals and per-subcarrier unwrapped phases (radians) via
+/// 0.8–2.0 Hz bandpass + autocorrelation peak detection.
+///
+/// Python:
+/// ```python
+/// from wifi_densepose import HeartRateExtractor
+///
+/// hr = HeartRateExtractor.esp32_default()  # 56 subcarriers, 100 Hz, 15s window
+///
+/// # Feed residuals and matching unwrapped phases from your preprocessor.
+/// # Unlike BreathingExtractor weights, phases=[] is invalid for heart-rate
+/// # extraction because the Rust core requires phase data for each subcarrier.
+/// est = hr.extract(residuals=[0.01, -0.02, …], phases=[0.0, 0.01, …])
+/// if est is not None:
+///     print(est.value_bpm, est.confidence)
+/// ```
 #[pyclass(name = "HeartRateExtractor")]
 pub struct PyHeartRateExtractor {
     inner: HeartRateExtractor,
@@ -265,10 +280,17 @@ impl PyHeartRateExtractor {
         Self { inner: HeartRateExtractor::esp32_default() }
     }
 
-    /// Extract heart rate from per-subcarrier residuals. GIL released
-    /// during DSP.
-    fn extract(&mut self, py: Python<'_>, residuals: Vec<f64>, weights: Vec<f64>) -> Option<PyVitalEstimate> {
-        let est = py.allow_threads(|| self.inner.extract(&residuals, &weights));
+    /// Extract heart rate from per-subcarrier residuals and matching
+    /// per-subcarrier unwrapped phases (radians). Empty phases are invalid
+    /// and return `None` because the Rust extractor requires phase data.
+    /// GIL released during DSP.
+    fn extract(
+        &mut self,
+        py: Python<'_>,
+        residuals: Vec<f64>,
+        phases: Vec<f64>,
+    ) -> Option<PyVitalEstimate> {
+        let est = py.allow_threads(|| self.inner.extract(&residuals, &phases));
         est.map(PyVitalEstimate::from_rust)
     }
 
diff --git a/python/tests/test_vitals.py b/python/tests/test_vitals.py
index a195d89a..942d2960 100644
--- a/python/tests/test_vitals.py
+++ b/python/tests/test_vitals.py
@@ -185,10 +185,44 @@ def test_heart_rate_explicit_ctor() -> None:
 
 def test_heart_rate_extract_returns_none_with_too_few_samples() -> None:
     hr = HeartRateExtractor.esp32_default()
-    out = hr.extract(residuals=[0.0] * 56, weights=[])
+    out = hr.extract(residuals=[0.0] * 56, phases=[0.0] * 56)
     assert out is None
 
 
+def test_heart_rate_extract_rejects_old_weights_keyword() -> None:
+    hr = HeartRateExtractor.esp32_default()
+    with pytest.raises(TypeError):
+        hr.extract(residuals=[0.0] * 56, weights=[0.0] * 56)
+
+
+def test_heart_rate_extract_with_synthetic_signal_and_phases() -> None:
+    """Drive the extractor with a synthetic 1.2 Hz sine (72 BPM) plus
+    same-length phase data. This proves the binding feeds Rust's required
+    `phases` slice instead of an empty vector that would keep returning None."""
+    hr = HeartRateExtractor.esp32_default()
+    sample_rate = 100.0
+    target_freq = 1.2  # 72 BPM
+    n_samples = int(60 * sample_rate)
+    phases = [i * 0.01 for i in range(56)]
+
+    produced_estimate = False
+    rng = Random(43)
+    for i in range(n_samples):
+        t = i / sample_rate
+        base = math.sin(2.0 * math.pi * target_freq * t)
+        residuals = [base + rng.gauss(0.0, 0.01) for _ in range(56)]
+        est = hr.extract(residuals=residuals, phases=phases)
+        if est is not None:
+            produced_estimate = True
+            assert math.isfinite(est.value_bpm)
+            assert 0.0 <= est.confidence <= 1.0
+            break
+
+    assert produced_estimate, (
+        "HeartRateExtractor never produced an estimate after 60s of synthetic data"
+    )
+
+
 # ─── Build feature flag ──────────────────────────────────────────────
 
 
diff --git a/v2/crates/wifi-densepose-sensing-server/src/field_bridge.rs b/v2/crates/wifi-densepose-sensing-server/src/field_bridge.rs
index 8c009e23..5b7f588f 100644
--- a/v2/crates/wifi-densepose-sensing-server/src/field_bridge.rs
+++ b/v2/crates/wifi-densepose-sensing-server/src/field_bridge.rs
@@ -7,12 +7,22 @@
 //! score-based heuristic in `score_to_person_count`.
 
 use std::collections::VecDeque;
+use std::sync::LazyLock;
+use wifi_densepose_signal::hardware_norm::HardwareNormalizer;
 use wifi_densepose_signal::ruvsense::field_model::{
     CalibrationStatus, FieldModel, FieldModelConfig,
 };
 
 use super::score_to_person_count;
 
+/// Length-only canonicalizer for calibration frames (issue #1170 pattern,
+/// shared with `multistatic_bridge`). Raw ESP32 amplitudes arrive at the
+/// hardware's native width (HT20 ≈ 64, HT40 ≈ 128/192); the FieldModel is
+/// configured for the canonical 56-tone grid, and `feed_calibration` rejects
+/// any other width with `DimensionMismatch`. Resampling here (default 56)
+/// lets real HT40 nodes actually calibrate instead of silently feeding nothing.
+static CALIB_NORMALIZER: LazyLock<HardwareNormalizer> = LazyLock::new(HardwareNormalizer::new);
+
 /// Number of recent frames to feed into perturbation extraction.
 const OCCUPANCY_WINDOW: usize = 50;
 
@@ -99,15 +109,27 @@ pub fn occupancy_or_fallback(
 
 /// Feed the latest frame to the FieldModel during calibration collection.
 ///
-/// Only acts when the model status is `Collecting`. Wraps the latest frame
-/// as a single-link observation (n_links=1) and feeds it.
+/// Acts while the model is `Uncalibrated` or `Collecting`. The first fed frame
+/// flips a freshly-started (`Uncalibrated`) model to `Collecting` inside
+/// `feed_calibration`; without accepting the `Uncalibrated` state here the two
+/// gates deadlock and the frame count never leaves 0 (calibration/start yields
+/// an `Uncalibrated` model that nothing would ever advance). Wraps the latest
+/// frame as a single-link observation (n_links=1) and feeds it.
 pub fn maybe_feed_calibration(field: &mut FieldModel, frame_history: &VecDeque<Vec<f64>>) {
-    if field.status() != CalibrationStatus::Collecting {
+    if !matches!(
+        field.status(),
+        CalibrationStatus::Uncalibrated | CalibrationStatus::Collecting
+    ) {
         return;
     }
     if let Some(latest) = frame_history.back() {
-        // Single-link observation: [1][n_subcarriers]
-        let observations = vec![latest.clone()];
+        // Resample the raw amplitude vector onto the FieldModel's canonical
+        // 56-tone grid before feeding. Real HT40 nodes stream 128-wide frames;
+        // feeding those raw made every `feed_calibration` fail DimensionMismatch
+        // (swallowed at debug level), pinning frame_count at 0 even after the
+        // status-gate deadlock was fixed. Single-link observation: [1][56].
+        let canonical = CALIB_NORMALIZER.resample_to_canonical(latest);
+        let observations = vec![canonical];
         if let Err(e) = field.feed_calibration(&observations) {
             tracing::debug!("FieldModel calibration feed: {e}");
         }
@@ -180,4 +202,65 @@ mod tests {
         assert_eq!(positions.len(), 1);
         assert_eq!(positions[0], [3.0, 4.0, 5.0]);
     }
+
+    /// Regression: a freshly-started (`Uncalibrated`) field model must begin
+    /// collecting once frames arrive. Before the fix, `maybe_feed_calibration`
+    /// only fed while already `Collecting`, but only `feed_calibration` sets
+    /// `Collecting` — so the first frame was never fed and the count stayed 0.
+    #[test]
+    fn maybe_feed_calibration_advances_uncalibrated_to_collecting() {
+        let mut field = FieldModel::new(single_link_config()).expect("field model");
+        assert_eq!(field.status(), CalibrationStatus::Uncalibrated);
+        assert_eq!(field.calibration_frame_count(), 0);
+
+        // n_subcarriers defaults to 56; one single-link frame of that width.
+        let frame = vec![0.5_f64; 56];
+        let mut history: VecDeque<Vec<f64>> = VecDeque::new();
+        history.push_back(frame);
+
+        maybe_feed_calibration(&mut field, &history);
+
+        assert_eq!(
+            field.status(),
+            CalibrationStatus::Collecting,
+            "first frame must flip Uncalibrated -> Collecting"
+        );
+        assert_eq!(
+            field.calibration_frame_count(),
+            1,
+            "frame count must advance past 0"
+        );
+
+        // Subsequent frames keep accumulating while Collecting.
+        maybe_feed_calibration(&mut field, &history);
+        assert_eq!(field.calibration_frame_count(), 2);
+    }
+
+    /// Regression (#1170 pattern): a real HT40 node streams 128-wide amplitude
+    /// frames, but the FieldModel is a 56-tone grid. Before canonicalization,
+    /// `feed_calibration` rejected every frame with DimensionMismatch (swallowed
+    /// at debug), so frame_count stayed 0 even with the deadlock fixed. The feed
+    /// must resample 128 → 56 and actually accumulate.
+    #[test]
+    fn maybe_feed_calibration_resamples_wide_frames_and_accumulates() {
+        let mut field = FieldModel::new(single_link_config()).expect("field model");
+
+        // 128-wide frame (HT40), NOT the model's 56 — would DimensionMismatch raw.
+        let wide = vec![0.5_f64; 128];
+        let mut history: VecDeque<Vec<f64>> = VecDeque::new();
+        history.push_back(wide);
+
+        maybe_feed_calibration(&mut field, &history);
+
+        assert_eq!(
+            field.status(),
+            CalibrationStatus::Collecting,
+            "128-wide frame must resample to 56 and be accepted"
+        );
+        assert_eq!(
+            field.calibration_frame_count(),
+            1,
+            "wide frame must accumulate, not be silently dropped"
+        );
+    }
 }
diff --git a/v2/crates/wifi-densepose-sensing-server/src/main.rs b/v2/crates/wifi-densepose-sensing-server/src/main.rs
index 120eaf5d..419c5b10 100644
--- a/v2/crates/wifi-densepose-sensing-server/src/main.rs
+++ b/v2/crates/wifi-densepose-sensing-server/src/main.rs
@@ -4991,6 +4991,20 @@ async fn calibration_start(State(state): State<SharedState>) -> Json<serde_json:
 async fn calibration_stop(State(state): State<SharedState>) -> Json<serde_json::Value> {
     let mut s = state.write().await;
     if let Some(ref mut fm) = s.field_model {
+        // Guard: finalizing before enough empty-room frames have accumulated
+        // is a client-side sequencing error, not a server fault. Return a
+        // clear, structured message (with progress) instead of a 500 so the
+        // caller knows to keep the room empty and poll /calibration/status.
+        let have = fm.calibration_frame_count();
+        let need = fm.min_calibration_frames() as u64;
+        if have < need {
+            return Json(serde_json::json!({
+                "success": false,
+                "error": "Not enough calibration frames yet — keep the room empty and poll /calibration/status until frame_count reaches the target.",
+                "frame_count": have,
+                "frames_needed": need,
+            }));
+        }
         let ts = chrono::Utc::now().timestamp_micros() as u64;
         match fm.finalize_calibration(ts, 0) {
             Ok(modes) => {
@@ -5030,6 +5044,18 @@ async fn calibration_status(State(state): State<SharedState>) -> Json<serde_json
     }
 }
 
+/// Compatibility surface used by the bundled dashboard. Activity history is
+/// not persisted by the Rust server yet, so return an honest empty collection
+/// instead of advertising the endpoint and responding with 404.
+async fn pose_activities() -> Json<serde_json::Value> {
+    Json(serde_json::json!({
+        "activities": [],
+        "total": 0,
+        "persisted": false,
+        "message": "Activity history is not persisted by the Rust sensing server.",
+    }))
+}
+
 /// Generate a simple timestamp string (epoch seconds) for recording IDs.
 fn chrono_timestamp() -> u64 {
     std::time::SystemTime::now()
@@ -7768,6 +7794,13 @@ async fn main() {
         .route("/api/v1/pose/current", get(pose_current))
         .route("/api/v1/pose/stats", get(pose_stats))
         .route("/api/v1/pose/zones/summary", get(pose_zones_summary))
+        .route("/api/v1/pose/activities", get(pose_activities))
+        // Dashboard-compatible aliases for the field-model calibration API.
+        .route("/api/v1/pose/calibrate", post(calibration_start))
+        .route(
+            "/api/v1/pose/calibration/status",
+            get(calibration_status),
+        )
         // Stream endpoints
         .route("/api/v1/stream/status", get(stream_status))
         .route("/api/v1/stream/pose", get(ws_pose_handler))
diff --git a/v2/crates/wifi-densepose-signal/src/ruvsense/field_model.rs b/v2/crates/wifi-densepose-signal/src/ruvsense/field_model.rs
index 2653fef1..210e6d0a 100644
--- a/v2/crates/wifi-densepose-signal/src/ruvsense/field_model.rs
+++ b/v2/crates/wifi-densepose-signal/src/ruvsense/field_model.rs
@@ -449,6 +449,11 @@ impl FieldModel {
             .map_or(0, |ls| ls.observation_count())
     }
 
+    /// Minimum frames required before `finalize_calibration` will succeed.
+    pub fn min_calibration_frames(&self) -> usize {
+        self.config.min_calibration_frames
+    }
+
     /// Feed a calibration frame (one CSI observation per link during empty room).
     ///
     /// `observations` is `[n_links][n_subcarriers]` amplitude data.