fix(sleep,workouts): delete native strength sessions, honor Liquid setting on the Sleep hero, tier the "may be incomplete" warning

[DX23876]

Stacked on #23 (upstream sync) — this PR's diff is only the commit on top of that merge.

Three reports from a grilling session, bundled onto one branch (same review pass, no migration on any of them).

Native strength sessions were visible but undeletable. deleteWorkout swept strap namespaces by natural key, but a native row is a read-time projection of trainingWorkoutNative with no workout row behind it — the sweep matched nothing and the session reappeared on reload. deleteNativeWorkoutRow now removes the native workout (exercises/sets cascade via FK), its trainingSessionLink, and the legacy manual "Strength Training" twin hidingLegacyStrengthRecordings was hiding — deleting the native alone would have uncovered that twin and made the delete look ignored again. isLegacyStrengthTwin also gained a zero-length fallback (a start/stop inside the same second has no "half" to overlap under the ratio test).

Everything else in the original report (deletion touching only the active strap, sub-minute sessions) turned out to already be fixed by #23's upstream sync (ryanbr#2286, ryanbr#2287). Confirmed no duration floor was missing on the strength-save paths either — both already refuse zero-completed-set sessions regardless of elapsed time.

Sleep hero stayed on the liquid gauge with Liquid Design off. SleepView.restHero drew LiquidScoreGauge unconditionally. It now reads TodayDashboardStyle.storageKey like every other screen: .liquid keeps the vessel gauge, every other style draws GlowRing on a plain card like Classic Today.

"May be incomplete" fired on nights that weren't short. The badge was driven by stagingSparse alone (thin motion coverage), not by whether the night actually read short — on a sample history 57/92 computed nights were sparse, including 10.5h/12h/12.75h nights. sparseStagingNote now tiers it: prominent only when the night is under 70% of the 30-day typical (or under 4h with fewer than 5 scored nights), a quiet footnote otherwise, stepping down when the stronger partial-timeline note (ryanbr#1716) is already shown. showsMotionStrip stops captioning "No movement detail" on imported/pre-migration nights that never carried per-epoch motion.

Two smaller fixes from the same pass: SleepModel.alignedMotion trims a fragment's persisted motion trace to the window a hand-edited night now shows (previously drawn unclipped from the detected start, so a moved onset/wake put restless bursts under the wrong stage bands). A new always-on diagnostic line (once per session per launch) logs when a kept session staged with no per-epoch motion, naming duration/stagingSparse/Motion-aware-Wake state without asserting a cause — needs a Test Centre log from a reporter to triage further.

Mirrored in both hosts that render the note (SleepView, StagesCard) off shared static helpers so they can't disagree.

Verified: swift test green — WhoopStore 755 (incl. new deleteTrainingSessionLinks test), StrandDesign 147 (5 pre-existing locale-dependent failures confirmed present before this diff too). xcodebuild test green for StrandTests, 3405 tests, 0 failures — run twice, including after a mid-session git reset --hard recovery, to confirm nothing was lost. xcodebuild build green for NOOPiOS (this fork's default CI doesn't build app targets). i18n_audit.py --ci exits 0 for the one new string (all nine languages). doc_comment_lint clean. Not tested on a real strap — nothing here touches BLE.

Analysis migration required: no — no scoring formula, analytics window, or persisted-value meaning changed; stagingSparse is read exactly as before, just presented differently.

Separately found, not part of this change: Tools/tests/test_parity_governance_acceptance.py and Tools/tests/test_rr_legacy_preservation_contract.py reference android/ paths this fork removed on 2026-08-14, and the parity-governance baseline reads stale after the sync. Correction to an earlier note here: these do NOT break tools-python.yml's active linux-capture job (its "Run Tools/ tests" step only runs the six top-level Tools/test_*.py modules, never Tools/tests/) — they break the separate, undocumented .github/workflows/parity-governance.yml. See #25, which retires that whole stack. #23 also needed two small, unrelated CI fixes of its own (12 new untranslated literals from upstream's own sync content, and the same two-line test fix #25 makes, cherry-picked since #25 is base-main and independent).

🤖 Generated with Claude Code

[DX23876]

Landed on main as 503eb24, cherry-picked on top of the 11.8.0 upstream sync rather than merged, which is why this branch still reads as conflicting. The diff is unchanged apart from the string-catalog and translation files, where the entries were three-way merged with the sync's own.

One follow-up the sync required: upstream ryanbr#2296 replaced RescoreBackgroundPolicy's pass-duration budget with CPU pacing, so DeferredRescorePlanTests no longer compiled against the old decide signature. It now pins the outstanding-debt rule instead (a2d2931).

Verified on the merged state: StrandTests 3414 tests / 0 failures, WhoopStore 755 / 0 failures, NOOPiOS builds and is installed on a device, i18n_audit.py --ci exits 0 and doc_comment_lint is clean. Closing as landed.