fix(analytics): always populate user email/period start/period end in report metadata

[kostiantyn-pshenychnyi1]

Summary

Fixes EPMCDME-13643 — the follow-up to #433 which partially wired meta.userEmail, meta.periodStart, meta.periodEnd into analytics reports.

Before this PR only codemie analytics --from A --to B --report --report-format json populated all three fields. Every other invocation shape leaked partial or missing metadata:

Invocation	userEmail	periodStart	periodEnd
--report (bare)	✅	❌	❌
--last 7d --report	✅	✅	❌
--session <id> --report	✅	❌	❌
--project X --branch Y --report	✅	❌	❌
--from A --to B --report	✅	✅	✅

Every shape now populates all three. Verified end-to-end on the linked local build.

Changes

• buildPayload() fallback derivation (src/cli/commands/analytics/report/payload-builder.ts) — tracks min(startTime) / max(startTime + duration) across the flattened ReportSessionRecord[] in the same pass that already computes totals. When the caller doesn't stamp explicit periodStart / periodEnd, meta falls back to those derived values. buildPayload stays a pure function (no I/O, no config reads, no env access). Also covers the OTEL and agent-exit callers for free.
• NaN / Infinity guard — Number.isFinite on both startTime and duration, so a single malformed session doesn't crash report generation via new Date(NaN).toISOString() RangeError. (Added in response to code-review CR-001.)
• parseFilterOptions() --last sets toDate (src/cli/commands/analytics/index.ts) — one-line fix. The user's implied "from N ago to now" contract is now honored at the caller layer.
• BaseAgentAdapter.maybeWriteSessionReport() ConfigLoader fallback (src/agents/core/BaseAgentAdapter.ts) — when CODEMIE_PROFILE_CONFIG is absent, malformed, or lacks userEmail, fall back to ConfigLoader.loadMultiProviderConfig().userEmail. Both lookups remain non-fatal.
• Vitest coverage — 6 new cases in payload-builder.test.ts (min derivation, max derivation, regression guard, duration=0 edge, zero-sessions omission, startTime≤0 skip), 1 fix-up case for NaN/Infinity; 4 new cases in analytics-cli-metadata.test.ts covering --last, --session, --project+--branch, bare wiring; 4 new cases in BaseAgentAdapter-session-report.test.ts for the ConfigLoader fallback.
• JSDoc contract update on ReportMeta.periodStart / periodEnd — from "absent for unfiltered reports" to "always present when the report contains any sessions".

session-report.ts is unchanged (its per-session derivation was already correct and is the reference pattern this PR mirrors).

Impact

Before — bare codemie analytics --report --report-format json:

{ "meta": { "userEmail": "u@example.com" } }

After — same command:

{
  "meta": {
    "userEmail": "u@example.com",
    "periodStart": "2026-01-13T09:17:11.262Z",
    "periodEnd":   "2026-07-27T09:49:08.872Z"
  }
}

No CLI surface changes, no schema breaks (fields stay TypeScript-optional), no new dependencies.

Checklist

• Self-reviewed (multi-lens SDLC code review: docs/superpowers/tasks/2026-07-27-analytics-report-always-populate-fields/code-review-final.json, one round of fixes recorded in code-review-check.json)
• Manual testing performed (all 5 invocation shapes verified against local linked build)
• Documentation updated (JSDoc contract change on ReportMeta; full SDLC artifacts under docs/superpowers/tasks/2026-07-27-analytics-report-always-populate-fields/)
• No breaking changes (fields stay optional; only expands when fields appear, never removes any)

Test plan

• npm run test:unit — 2397 pass / 1 skipped
• npm run typecheck — clean
• npm run build — clean
• npm run license-check — clean
• npx commitlint --from origin/main --to HEAD — clean
• Manual E2E on rebuilt CLI: bare, --last 7d, --session <id>, --project X --branch Y, --from A --to B — all populate the three fields; --from/--to values preserved
• Baseline noise on main (unrelated, pre-existing — see qa-report.md): npm run lint fails on 5 files this PR does not touch; npm run test:integration fails on 6 suites due to missing node-pty locally and Windows subprocess crashes in skills.test.ts

Ref EPMCDME-13643