fix(tracker): exclude Lost tracks from bridge output (#420, ADR-082)

[ruvnet]

Fixes #420.

Symptom

3× ESP32-S3 nodes streaming CSI to the Rust sensing server. GET /api/v1/sensing/latest reports estimated_persons: 1. The live UI renders 22-24 phantom skeletons that flicker at high rate.

Root cause

crates/wifi-densepose-sensing-server/src/tracker_bridge.rs::tracker_to_person_detections documented itself as:

Only tracks whose lifecycle is_alive() are included.

…but called tracker.active_tracks(), which itself filters by is_alive(). is_alive() returns true for Tentative ∪ Active ∪ Lost — every non-Terminated state. The bridge therefore shipped all non-terminated tracks to the WebSocket stream.

Lost tracks are deliberately kept in the tracker for reid_window (~3 s by default) so re-identification can match them when a similar detection reappears. They are by definition not currently observed (they've missed loss_misses updates already). Rendering them as live skeletons is the bug.

With 3 nodes × 10 Hz CSI, every Mahalanobis-gate miss creates a new Tentative track and ages the previous one to Lost. Up to reid_window × n_nodes ≈ 90 phantom Lost tracks can co-exist at once. The actually-observed person is one of them; the rest are ghosts.

Fix

• Add PoseTracker::confirmed_tracks() — returns only Tentative ∪ Active. (Tentative is included so first-detection visibility latency stays at one tick.)
• Rewire tracker_to_person_detections to call confirmed_tracks().
• active_tracks() is unchanged — AETHER re-ID consumers (ADR-024) need the full alive set.
• Re-export TrackerConfig from signal::ruvsense so consumers can construct configured trackers without reaching into pose_tracker::.

Pure egress filter. No state-machine change. No schema change.

ADR

ADR-082 — Pose Tracker Confirmed-Track Output Filter included in this PR. Status: Accepted.

Validation

$ cargo test --workspace --no-default-features
… 1,539 passed, 0 failed, 8 ignored

New regression test test_lost_tracks_excluded_from_bridge_output:

1. Drives a track to Active over 2 hits.
2. Submits empty detections for loss_misses + 1 cycles → track transitions to Lost.
3. Asserts tracker_update(empty) returns Vec::new().
4. Asserts the Lost track is still in tracker.all_tracks() (re-ID still works).

ESP32-S3 on COM7 streamed unmodified firmware throughout — verified live CSI cb #32800, RSSI −46 dBm.

Test plan

• cargo test --workspace --no-default-features → 1,539 / 0
• New regression test passes
• Existing test_tracker_update_stable_ids still passes (Tentative→Active path unaffected)
• ESP32-S3 unaffected
• CI: workspace tests on Linux + Windows runners

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