perf(wifi-densepose-sar): incremental phasor rotation in backprojection (~4.4-4.5x, MEASURED)

focus_at_point called Complex64::from_polar (a sin/cos pair) once per
(pose, frequency) term. FrequencySweep::frequencies() produces evenly
spaced frequencies by construction, so the per-term phase is an
arithmetic progression in the frequency index -- the phasor can be
evaluated once per pose and advanced by a fixed complex-multiply step
per frequency instead, turning K trig evaluations into 2.

focus_at_point's signature changes from a raw &[f64] frequency slice
to &FrequencySweep, so the evenly-spaced-frequencies precondition
this optimization depends on is a type-level invariant rather than a
caller-observed one -- an arbitrary non-uniform frequency list is no
longer constructible through this API at all.

MEASURED (criterion regression detection, p < 0.001): ~4.4-4.5x
faster across 512/4096/32768-voxel grids (300us/1.97ms/14.5ms vs the
prior 1.47ms/10.4ms/73.5ms). Proven equivalent, not just faster: a new
test independently reimplements the direct per-frequency computation
as a reference and checks the optimized path against it across four
sweep sizes (incl. the n_steps=1 degenerate case) and both on-target
and off-target points, to <1e-9 relative error.

25 tests (22 unit + 3 integration), 0 failed, clippy-clean.

CHANGELOG.md

@@ -9,7 +9,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Added
 
-- **`wifi-densepose-sar` — coherent wideband RF tomography research crate (ADR-283).** New standalone leaf crate (the `nvsim` pattern; zero coupling to `wifi-densepose-hardware` or any real ingestion path) implementing the synthetic-aperture-radar reconstruction primitive a handheld through-wall RF imaging device would need — motivated by comparison against Applied Electrodynamics' "WaveSight" launch, and explicitly scoped below ADR-278's RISE/DiffRadar/GeRaF reproduction gates. Ships: (1) a stepped-frequency, multi-position complex forward measurement simulator (`y_{m,k} = Σ σ_j/R² · exp(-i·4π·f·R/c) + noise`, deterministic ChaCha20 seeding); (2) delay-and-sum backprojection reconstruction onto a 3D voxel grid, rayon-parallelized over voxels; (3) threshold + local-maximum point-cloud extraction; (4) closed-form range/cross-range resolution and antenna-pose coherence-budget formulas (`ΔR=c/2B`, `δ_CR≈λR/2L`, `Δp≤λ/8`) checked against the reconstruction's *actual* behavior in `tests/physics_validation.rs` rather than merely documented — forward-simulating two targets at controlled separations and proving they resolve or merge exactly where the formulas predict, and that reconstructed focus at a known target degrades as injected antenna-pose error grows. Every number is SYNTHETIC/L0 (ADR-282) — no real wideband RF hardware backs this crate; see the crate README and `docs/tutorials/coherent-rf-tomography-backprojection.md` for the full honesty boundary and a worked walkthrough. 24 tests (21 unit + 3 integration), 0 failed, clippy-clean; MEASURED backprojection throughput ~350-450K voxels/sec (criterion, 21 poses × 32 freq steps).
+- **`wifi-densepose-sar` — coherent wideband RF tomography research crate (ADR-283).** New standalone leaf crate (the `nvsim` pattern; zero coupling to `wifi-densepose-hardware` or any real ingestion path) implementing the synthetic-aperture-radar reconstruction primitive a handheld through-wall RF imaging device would need — motivated by comparison against Applied Electrodynamics' "WaveSight" launch, and explicitly scoped below ADR-278's RISE/DiffRadar/GeRaF reproduction gates. Ships: (1) a stepped-frequency, multi-position complex forward measurement simulator (`y_{m,k} = Σ σ_j/R² · exp(-i·4π·f·R/c) + noise`, deterministic ChaCha20 seeding); (2) delay-and-sum backprojection reconstruction onto a 3D voxel grid, rayon-parallelized over voxels; (3) threshold + local-maximum point-cloud extraction; (4) closed-form range/cross-range resolution and antenna-pose coherence-budget formulas (`ΔR=c/2B`, `δ_CR≈λR/2L`, `Δp≤λ/8`) checked against the reconstruction's *actual* behavior in `tests/physics_validation.rs` rather than merely documented — forward-simulating two targets at controlled separations and proving they resolve or merge exactly where the formulas predict, and that reconstructed focus at a known target degrades as injected antenna-pose error grows. Every number is SYNTHETIC/L0 (ADR-282) — no real wideband RF hardware backs this crate; see the crate README and `docs/tutorials/coherent-rf-tomography-backprojection.md` for the full honesty boundary and a worked walkthrough. `focus_at_point` exploits the evenly-spaced-by-construction frequency sweep (an arithmetic progression in per-term phase) to evaluate each pose's phasor once and advance it by a fixed complex-multiply step per frequency instead of one `sin`/`cos` pair per frequency — **MEASURED ~4.4-4.5x faster** (criterion regression detection, p < 0.001) than the first-shipped direct-computation version, proven equivalent (not just faster) to an independently reimplemented reference across four sweep sizes and on-/off-target points. 25 tests (22 unit + 3 integration), 0 failed, clippy-clean; MEASURED backprojection throughput ~1.7-2.3M voxels/sec (criterion, 21 poses × 32 freq steps).
 - **HOMECORE platform runtime completion — secure native/Wasmtime plugins, authenticated HAP IP, expanded Home Assistant APIs, durable restoration/migration, and voice protocols.** `homecore-server` now owns deterministic compiled-in native plugin registration plus explicitly configured, path-bounded, Ed25519 publisher-verified Wasm packages executed through Wasmtime with setup/state-change/teardown lifecycle; arbitrary native dynamic libraries remain intentionally unsupported. The optional HAP server implements persisted accessory identity and controller records, SRP-6a Pair-Setup M1–M6, X25519/Ed25519 Pair-Verify M1–M4, HKDF-SHA512/ChaCha20-Poly1305 record framing, authenticated/admin endpoint gates, replay/tamper closure, live entity synchronization, and paired-state `_hap._tcp` mDNS updates (45 focused tests; external Apple certification is not claimed). Startup restores device/entity registries and deterministic latest recorder states before plugins, and migration now atomically preserves forward-compatible device/config-entry fields. The HA-compatible surface adds events, templates, config checks, components, registries, history/logbook with SQL-enforced global response bounds, calendar/camera provider routes, and modern WebSocket negotiation while retaining a machine-readable limitations matrix for integration-specific behavior. Assist adds bounded PCM16, async STT/TTS contracts, an end-to-end speech pipeline, and an authenticated satellite session protocol; real deployments still provide the speech engines.
 - **`ruview-unified` increment 3 — Gaussian update-loop completion, separable delay-Doppler, and property-tested boundary hardening.** (1) `GaussianMap::merge_overlapping` (ADR-275 step 5: mutual-Mahalanobis + semantic-compatibility dedup catching drift the insert-time gate misses) and lifetime-aware decay (`τ_eff = τ·(1+ln(1+lifetime/τ))` — confirmed structures outlive transients at equal nominal τ). (2) `delay_doppler_map` reimplemented separably (`O(B²S+S²B)`), proven equivalent to the direct reference to <1e-10 and **measured 8.3× faster** (520 µs vs 4.34 ms at 56×8). (3) `tests/security_boundaries.rs` — 8 `proptest` properties over the boundary surfaces (arbitrary values incl. NaN/±inf via `f64::from_bits`) that found and fixed three input-controlled defects: a BLE-CS phase-unwrap infinite loop on non-finite phases and an ~1e299-iteration loop on finite-huge phases (now O(1) modular unwrap + plausibility bound), and a subnormal Gaussian scale overflowing `1/σ²` to NaN density (now physical σ/occupancy bounds). (4) New criterion benches for all increment-2 hot paths (`to_canonical` 38 µs, `ble_cs_range` 481 ns, AoI planner 647 ns/200 regions, coherent fusion 1.5 µs/32 members, factorized pose 521 ns). ruview-unified now 98 tests (87 lib + 3 acceptance + 8 security), 0 failed, clippy-clean.
 - **`ruview-unified` increment 2 — native frame contract + programmable perception (ADR-279..282).** (1) `RfFrameV2` becomes the authoritative RF record: native complex IQ with explicit validity masks, declared `PhaseState`, TX/RX poses + antenna geometry in one building frame, calibration/quality state, and a provenance rule enforced at construction — `Synthetic ⇒ L0Simulation` and `Measured ⇒ ≥ L1CapturedReplay` can never alias (the public L0–L5 evidence ladder is now a type); the 56-bin canonical tensor is demoted to a derived compatibility view (`to_canonical`, mask-aware gap-filling through the same normalization path as every adapter; native samples proven byte-untouched). (2) Active sensing control plane (`control.rs`): ETSI-ISAC-vocabulary `SensingTask` admission (raw export always refused; identity requires consent), `SensingAction`/`InformationGoal`, an age-of-information `ActiveSensingPlanner` (priority = uncertainty × change rate × criticality ÷ cost; **measured 95% sensing-traffic reduction** vs uniform refresh on a 20-region scenario), fail-closed `CoherentSensorGroup` fusion gates (time/phase/geometry bounds; five denial paths tested), policy-authorized RIS/movable-antenna actuation receipts, and purpose-scoped `TaskSufficientRepresentation` leakage validation. (3) New modality surfaces: BLE Channel Sounding adapter + `ble_cs_range` treating phase-slope and RTT as **separate cross-validated evidence** (exact distance recovery on synthetic tones; relay-style divergence flagged, never averaged), delay-Doppler-native `FieldAxis` + `delay_doppler_map` (unit-peak tone test), IEEE P3162 synthetic-aperture import profile. (4) RePos-factorized pose head (relative skeleton on the content representation, root on the geometry-conditioned one, calibrated per-joint uncertainties): held-out-room MPJPE 0.0003 m vs 0.2534 m for the monolithic baseline in the room-shortcut leakage experiment; ≤2% structured-adapter budget (740 params). (5) Age gate input now `log(1+age_ms)` per the age-aware-CSI recipe (gradient check re-proven); Gaussian primitives gained `first_seen_ns`/`doppler_variance`/bounded `source_receipts` lineage; `PartitionKey` gained a `session` dimension and `SplitManifest` certifies disjointness across all seven dimensions. 87 tests, 0 failed; crate clippy-clean. Docker images unaffected (no shipped binary consumes the crate yet); Python proof re-verified PASS.