feat(report): emit markdown

[PeGa]

focus report now emits markdown on stdout. Same two queries, new renderer.

focus report custom 14 > report.md

Why

Notes are hand-written markdown — bullets, **bold**, > blockquotes. The old layout indented every note line behind a seven-space 📝 prefix, which turned all of it into code blocks, so producing a shareable report meant reassembling the output by hand.

Shape

# Focus report
## Last 14 days

Period: 2026-08-20 → 2026-09-03 Total: 67h 39m across 25 sessions

---

## Projects

| Project | Time | Sessions |
|---|---:|---:|
| `fyc/bloque-de-trabajo` | 12h 20m | 1 |

---

## Sessions

### [29] `fyc/deploy-wells-planning-develop-migrations`
**2026-09-02 18:45–01:45 · 7h 0m**

<note, verbatim>

Rules separate sessions from each other, so the last session isn't left with one dangling. An empty period stops after the period line rather than trailing a rule off a blank document.

Verified against real data

Rendering a 15-day window from a copy of the live DB and diffing the project table against an existing hand-assembled report: byte-identical rows, and all 25 of its sessions in identical order. The only differences were a session logged after that report was written, and the issue #36 duplicate row still present in the DB (fyc/sesion-de-trabajo id 13, same start timestamp to the second as id 12) — data, not rendering.

Notes

• _report is the only thing rewritten. The today|week|month|custom dispatch, wants_help, db_ensure and usage_error are untouched; --help still exits 0 and bad arguments still exit 2.
• Aggregation stays in SQL — no declare -A, so bash 3.2 still works (PORT-BASH32).
• core/text.sh notes_block stays; off and past list still use it.
• Table cells need no pipe escaping: the sessions table CHECKs that project names contain no |.
• s/e now fall back to the stored string when a timestamp won't parse, matching past list — previously one unreadable timestamp aborted the whole report under set -e.

13 new assertions covering the skeleton, both time-line forms, unindented note bullets, no dangling rule, and the empty-period case. audit clean, state-matrix 154/154, time-portability 20/20.