fix: preserve daily timestamp declarations across gap consumers #103

Actual reproduction

On session prerequisitef57c8d91fd5dbada151fb4dfe8325bda8268b954, real SyntheticProvider daily July11/14 OHLCV is normalized to Tokyo-midnight session labels, written through Flat/Hive storage with version-2 JPX/session_label/Asia-Tokyo metadata, and read through the actual canonical-UTC storage and DataManager metadata API. Stored civil UTC dates are July10/13. The daily gap utility ignores declared label timezone and falsely reports missing FridayJuly11; the separate range planner correctly restores the declaration and is a passing control. This is a numerical boundary defect, not a new API keyword error.

Additional accepted calendar requirements remain unsupported: both daily gap consumers reject explicit event_time/bar_close rather than mapping their true authoritative sessions. Continuous midnight right labels must use the previous session, and daily frequency cannot override explicit instant semantics. Current actual workflow regressions:10 failures/4 passing controls in1.34s, daily-timestamps-base.log. The unsupported-mode failures are capability evidence, not10 historical numerical defects.

Required implementation

Reuse shared declaration resolution and native SessionAssigner interpretation, with one internal daily-label projection used by both gap consumers and backfill provider-row selection. Restore a declared timezone before interpreting aware session labels; naive session labels remain civil identifiers, not localized event clocks. Explicit event/close/bar-side declarations use actual native session membership; out-of-session instants fail clearly, while legacy label classification retains its existing off-session-label policy. Missing-data classification remains separate from filling, and input/provider rows remain unchanged.

Range bounds remain inclusive session labels at UTC midnight, utility DataGap bounds remain the actual bracketing observations. Daily missing_periods/size_days count scheduled sessions, not observed dates or elapsed days. ExplicitNone bypasses schedule projection. Test actual Flat/Hive storage, event/close midnight sides, real missing session, timezone restoration, custom timestamp column, no-calendar controls and actual backfill acquisition, not only the helper.

Depend on PR94, keep one focused issue/PR, and reconcile intraday PR100 separately when branches land. All applicable full main-target CI/docs/package/resource gates required before routine merge. Preserve immutable0.2.1; no release/deploy or heavy local full suites during reservation. AI-assisted maintenance under owner direction.