fix(parser): keep both halves of a midnight-straddling turn, and stop --provider leaking claude

[ozymandiashh]

Ports upstream fixes for two defects this branch never received. Both are conservation bugs: work that happened is not where the report says it is.

A turn spanning local midnight was filtered as a unit

The range and day filter keyed on the turn's first call, so every later call that landed in the requested day was discarded along with it. A long autonomous Codex run, or Claude work that crossed midnight, made codeburn today under-report until the turn ended — and multi-day totals attributed the whole turn to its start day.

Filters now slice inside the turn. Only the calls inside the requested window survive, and the turn's timestamp re-anchors to its first surviving call, so turn-anchored rollups (category, editTurns, oneShotTurns, the daily cache) land on the day the retained calls actually happened. Cost, calls, savings and tokens bucket under each call's own local day, so day N + day N+1 conserves the whole-range total.

A sliced turn is still classified from its full call list — category, hasEdits and retries describe the whole exchange, not the surviving slice. That matches the Claude path and is deliberate.

The inverse leak, on provider-filtered runs

--provider <other> still entered the claude scan, whose orphan pass read the entire cached claude section, treated every cached PR-bearing transcript as no-longer-discovered, and re-injected it. By Project and By Model listed Anthropic spend under --provider cursor while the headline showed cursor alone.

Now guarded by an explicit in-scope check — deliberately not a directory-count check, so when claude is in scope but every transcript has been pruned, PR-attributed orphans still survive.

Blast radius

Daily-history rows and the JSON daily fallback change shape for straddling days: call-derived values move to the call's own day. Session totals and the session-cache format are unchanged.

Two caveats, stated rather than left to be found

1. The multi-day all-provider By Activity rollup still derives today's slice from the unsliced range parse, so a straddling turn's category cost stays anchored on its start day and categories can sum below the headline on that surface. Upstream has a follow-up; it should land next.
2. This PR does not bump the daily cache version, on purpose. A single bump in the release covers every parser-behaviour change landing with it, and fix(codex): validate rollouts structurally, guard the parse path #926 carries it. Three PRs each editing that constant would conflict on the same line and leave you asking which "16" is which. If this and fix(codex): validate rollouts structurally, guard the parse path #926 land apart, an upgrading user with a finalized rollup keeps turn-anchored days until something else forces re-hydration.

[ozymandiashh]

Converted to draft: this was opened with only a self-review by the model that wrote it, which is not the review bar this batch is held to. Independent review by two other reviewers is running now; I will mark it ready once both have passed and any findings are applied. Apologies for the noise.