fix(notifications): wire the maintainer-recap's calibration/gate-outcomes/per-repo section builders into the actual digest output

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Context

The maintainer recap digest (RecapReport, #1963) has four dedicated "content slice" section builders,
each shipped in its own file with a doc comment explicitly describing itself as a slice of the composed
digest:

• buildCalibrationRecapSection — src/services/maintainer-recap-calibration.ts (feat(notifications): calibration / reversal-rate section for the maintainer recap #2243): reversal count /
  reversal-rate section, needs only report.windowDays + report.totals.{merged,closed,reversals}.
• buildGateOutcomesRecapSection — src/services/maintainer-recap-gate-outcomes.ts (feat(notifications): gate-outcomes section for the maintainer recap (blocked / overridden / false-positive) #2242): blocked /
  overridden / false-positive section, needs only report.windowDays +
  report.totals.{blocked,gateFalsePositives,gateOverrides}.
• buildPerRepoRecapSection — src/services/maintainer-recap-per-repo.ts (feat(notifications): per-repo summary section for the maintainer recap #2241): a capped, sorted
  per-repo breakdown with a "(+N more)" remainder line, needs only report.windowDays + report.repos.
• buildDriftRecapSection — src/services/maintainer-recap-drift.ts (calibration: config-drift section in the maintainer recap #8214): a config-drift section.

All three fields these first three sections need (totals.merged/closed/reversals/blocked/ gateFalsePositives/gateOverrides, and repos) are already present on every RecapReport produced by
buildMaintainerRecap in src/services/maintainer-recap.ts — no new data sourcing is required to wire
them in.

Despite this, formatMaintainerRecap (src/services/maintainer-recap.ts, the function that actually
renders a RecapReport into the digest body posted to Discord/Slack) never calls any of them:

• buildCalibrationRecapSection and buildGateOutcomesRecapSection are never called anywhere in src/**
  outside their own unit tests (test/unit/maintainer-recap-calibration.test.ts,
  test/unit/maintainer-recap-gate-outcomes.test.ts) — confirmed by repo-wide grep. Fully implemented,
  fully tested, never composed into the real output.
• buildPerRepoRecapSection is also never called in production; formatMaintainerRecap instead inlines
  its own simpler, duplicate per-repo line format (the perRepoLines map at
  src/services/maintainer-recap.ts around line 168) that has no cap, no "(+N more)" remainder handling,
  and no sort — a second, drifted implementation of the same section sitting next to the unused dedicated
  one.
• buildDriftRecapSection's output IS renderable — formatMaintainerRecap accepts an optional
  options.configDrift: DriftRecapSection parameter and appends it when present (added for calibration: config-drift section in the maintainer recap #8214) — but
  runMaintainerRecap (the only production caller of formatMaintainerRecap, same file, around line 241)
  calls formatMaintainerRecap(report) with no options argument at all. The config-drift section is
  therefore never rendered in a real, delivered digest either; it is only exercised via
  test/unit/maintainer-recap-format.test.ts calling formatMaintainerRecap directly with a hand-built
  configDrift value.

This repo already has a recorded instance of exactly this bug shape (closed issue #6636:
"resolveDispositionReason is fully implemented and tested but never called from production code") — this
issue is the same pattern recurring across four sibling section builders in one feature area.

Net effect: a maintainer running the live recap digest today only ever sees the ad-hoc "Summary / Totals /
(duplicate, uncapped) Per-repo" text formatMaintainerRecap hand-rolls — never the calibration section, the
gate-outcomes section, the properly-capped per-repo section, or the config-drift section, even though all
four were separately scoped, built, and merged specifically to be part of this digest.

Requirements

1. In formatMaintainerRecap (src/services/maintainer-recap.ts), replace the inline perRepoLines
   block with a call to buildPerRepoRecapSection({ windowDays: report.windowDays, repos: report.repos })
   (imported from ./maintainer-recap-per-repo), rendering its .lines the same way the existing
   ## Per-repo section already renders (through recapSectionLines/redactRecapLine). Preserve the ## Per-repo header.
2. Add a ## Calibration section to formatMaintainerRecap's output, built by calling
   buildCalibrationRecapSection({ windowDays: report.windowDays, totals: report.totals }) (imported from
   ./maintainer-recap-calibration) and rendering its .lines through the same recapSectionLines/
   redactRecapLine path as every other section. This section is unconditional (not behind an optional
   options flag) since its inputs are always present on any RecapReport.
3. Add a ## Gate outcomes section the same way, via buildGateOutcomesRecapSection({ windowDays: report.windowDays, totals: report.totals }) (imported from ./maintainer-recap-gate-outcomes).
   Unconditional, same reasoning as point 2.
4. In runMaintainerRecap, pass a configDrift option through to formatMaintainerRecap whenever the
   caller supplied one. Add an optional configDrift?: DriftRecapSection field to
   runMaintainerRecap's own options parameter and forward it as
   formatMaintainerRecap(report, { configDrift: options.configDrift }). Do NOT attempt to source live
   drift data inside runMaintainerRecap itself (that requires querying the knob-loosening sentinel state
   in src/services/loosening-knobs.ts, which is a separate, larger concern with its own data-sourcing
   design) — this issue only needs the plumbing to exist so a caller that already has a DriftRecapSection
   (or a future caller that builds one) can pass it through and have it actually render. Leave a code
   comment noting that src/review/maintainer-recap-wire.ts (the real cron caller) does not yet supply one.
5. Keep the section ORDER as: Summary, Totals, Per-repo, Calibration, Gate outcomes, Config drift
   (optional, last) — Totals stays as-is (it is not one of the four dormant section builders and is
   already correct).
6. Do not change buildMaintainerRecap's RecapReport shape, and do not touch
   buildTopContributorsRecapSection (src/services/maintainer-recap-top-contributors.ts) — that section
   needs a contributors: TopContributor[] list that is NOT present on RecapReport today, so wiring it in
   requires a separate data-sourcing decision outside this issue's scope.

Deliverables

• formatMaintainerRecap renders ## Per-repo via buildPerRepoRecapSection instead of its own inline
  duplicate.
• formatMaintainerRecap renders a new, unconditional ## Calibration section via
  buildCalibrationRecapSection.
• formatMaintainerRecap renders a new, unconditional ## Gate outcomes section via
  buildGateOutcomesRecapSection.
• runMaintainerRecap accepts and forwards an optional configDrift option to formatMaintainerRecap.

Test Coverage Requirements

99%+ Codecov patch coverage, branch-counted, on every changed line in src/**. At minimum:

• formatMaintainerRecap: a report with populated repos/totals renders all three new/replaced sections
  with the same content the standalone section-builder unit tests already assert (cross-check against
  test/unit/maintainer-recap-calibration.test.ts / -gate-outcomes.test.ts / -per-repo.test.ts fixtures
  so the wired output matches the already-tested builder output exactly).
• An empty RecapReport (zero repos, zero totals) still renders all sections with their documented
  zero/empty-case text (each builder already has its own zero-case branch — assert the composed output
  reaches it).
• runMaintainerRecap forwards a supplied configDrift through to the rendered output, and omits the
  ## Config drift section entirely when none is supplied (existing behavior, must not regress).
• Update test/unit/maintainer-recap.test.ts and test/unit/maintainer-recap-format.test.ts for the new
  section content; do not delete existing assertions about Summary/Totals.

Expected Outcome

The live maintainer recap digest delivered to Discord/Slack actually contains the calibration,
gate-outcomes, and properly-capped per-repo sections that were separately scoped and shipped for exactly
this purpose (#2241, #2242, #2243), instead of silently omitting them in favor of ad-hoc inline text — and
a caller that supplies config-drift data can have it rendered without needing to bypass
runMaintainerRecap.

Links & Resources

• src/services/maintainer-recap.ts — formatMaintainerRecap, runMaintainerRecap (both to change).
• src/services/maintainer-recap-calibration.ts, -gate-outcomes.ts, -per-repo.ts, -drift.ts — the
  four dormant/partially-wired section builders.
• Closed issues feat(notifications): per-repo summary section for the maintainer recap #2241, feat(notifications): gate-outcomes section for the maintainer recap (blocked / overridden / false-positive) #2242, feat(notifications): calibration / reversal-rate section for the maintainer recap #2243, calibration: config-drift section in the maintainer recap #8214 — the original scoping issues for each section.
• Closed issue resolveDispositionReason is fully implemented and tested but never called from production code #6636 — the prior instance of this exact "implemented and tested but never called from
  production code" bug shape in this repo.
• test/unit/maintainer-recap*.test.ts — existing coverage to extend.

[linear-code]

JSO-5876