fix: open issue sweep and ESP32 v0.8.4 release - #1355

Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>

…d thermal risk

Lower the STA auth threshold from WPA2_PSK to WPA_PSK so routers running
WPA/WPA2-mixed compatibility mode aren't rejected with
WIFI_REASON_NO_AP_FOUND_IN_AUTHMODE_THRESHOLD (reason=211), and log the
disconnect reason/rssi instead of retrying blind. Also document the thermal
risk of running this firmware's continuous-radio, tier-2 DSP pipeline on
coin-sized clone boards (ESP32-S3-Zero, SuperMini) with minimal PCB copper
and budget regulators, after a field report of three such boards failing to
power on following a normal session.

Co-Authored-By: claude-flow <ruv@ruv.net>

POST /api/v1/calibration/start created the FieldModel in Uncalibrated, but
field_bridge::maybe_feed_calibration only fed frames while already Collecting
— and the only thing that sets Collecting is feed_calibration on its first
fed frame. The two gates deadlocked: no first frame was ever fed, so
calibration_frame_count stayed 0 and status never left Uncalibrated. Observed
live on a streaming ESP32 node as {"status":"Uncalibrated","frame_count":0}
that never advanced.

- field_bridge::maybe_feed_calibration: feed while Uncalibrated | Collecting
  so the first frame flips the model to Collecting and the count advances.
- calibration_stop: return structured {success:false, frame_count,
  frames_needed} instead of an opaque 500 when finalized with too few frames.
- FieldModel::min_calibration_frames() accessor for the guard above.
- Regression test: maybe_feed_calibration_advances_uncalibrated_to_collecting.

Presence/motion/vitals were unaffected (separate auto rolling baseline).

Co-Authored-By: claude-flow <ruv@ruv.net>

…(real HT40 fix)

Follow-up to the calibration deadlock fix. With the status gate unstuck,
maybe_feed_calibration reached feed_calibration, but a real ESP32 HT40 node
streams 128-wide amplitude frames while the single-link FieldModel is the
canonical 56-tone grid. LinkStats::update returned DimensionMismatch,
feed_calibration bubbled it, and maybe_feed_calibration swallowed it at debug
level — so frame_count stayed pinned at 0 on live hardware (presence/vitals,
which read the global history, were unaffected).

Resample 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 maybe_feed_calibration_resamples_wide_frames_and_accumulates
(128-wide -> Collecting + count 1). sensing-server bin: 173 passed, 0 failed.

Co-Authored-By: claude-flow <ruv@ruv.net>