release: v0.13.1 — mic chart defaults to psi (matches PDF)

v0.13.0 shipped the mic_unit_pref default as "dBL", which made the
website chart's mic axis inconsistent with the PDF report (which
renders psi).  Original brief was always "psi on charts, dBL on
peaks" — I implemented the default backwards.  Operator caught it
within an hour of rollout.

Same-day patch:
- backend/models.py: default "dBL" → "psi"
- migrate_add_mic_unit_pref.py: idempotent across both fresh DB
  ("add column with psi default") and v0.13.0 upgrade ("flip dBL
  rows to psi").  One-row table, freshness assumed.
- backend/routers/settings.py: GET/PUT fallback "dBL" → "psi"
- templates/settings.html: dropdown's `selected` flag moves to psi
  + reorders options + relabels with "(matches PDF report)" hint
- backend/static/event-modal.js: module-level fallback + branch
  conditions flip to make psi the unset/error default

Includes the "Captured at" → "Time received" relabel from earlier
in the day (already-shipped commit 43c804d) rolled into the
release notes.

Migration is idempotent + safe to re-run; rolled out on the dev
container during this commit's smoke test.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

CHANGELOG.md

@@ -5,6 +5,29 @@ All notable changes to Terra-View will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [0.13.1] - 2026-05-29
+
+Same-day patch on top of v0.13.0.  Fixes the mic-chart unit default — v0.13.0 shipped with `dBL` as the default, but the PDF report renders the mic axis in psi, so the website chart and the printed report didn't match.  Operator caught it within an hour of rollout.  Also relabels the modal's "Captured at" field to "Time received" so it isn't mistaken for the device's trigger time.
+
+### Fixed
+
+- **Event-detail modal: mic chart now defaults to psi**, matching the PDF report's mic axis.  The waveform/histogram chart's mic channel now renders in raw psi by default; operators who specifically prefer dB(L) on charts can flip it via Settings → General → "Event Report — Mic Channel Units".  Peaks everywhere else (table tiles, modal Peaks section, KPI summaries) stay in dB(L) as before — this is strictly a chart-axis change.
+- **Modal label: "Captured at" → "Time received"** (+ tooltip clarifying it's the SFM ingestion time, not the unit-local trigger time at the top of the modal).  Same change in seismo-relay's standalone webapp for consistency.
+
+### Migration Notes
+
+The bundled `backend/migrate_add_mic_unit_pref.py` is now idempotent across both the v0.13.0 "add column" path and the v0.13.0 → v0.13.1 default flip.  Existing rows sitting at the original `'dBL'` default (i.e. nobody touched the setting yet — true for almost everyone) get bumped to `'psi'` on migration.
+
+```bash
+cd /home/serversdown/terra-view
+docker compose build terra-view && docker compose up -d terra-view
+docker exec terra-view-terra-view-1 python3 /app/backend/migrate_add_mic_unit_pref.py
+```
+
+If you _did_ deliberately set the chart to dB(L) via Settings between v0.13.0 rollout and this patch, the migration will reset it — one click in Settings to restore.  Trade-off considered acceptable given the very small user base and the freshness of the v0.13.0 release.
+
+---
+
 ## [0.13.0] - 2026-05-29
 
 The "SFM integration Phase 1" release.  Closes the gap between Terra-View and the standalone SFM webapp on port 8200 — operators no longer need to bounce between the two for routine event review.  The shared event-detail modal (used on `/sfm`, `/unit/{id}`, `/admin/events`, and `/projects/{p}/nrl/{l}`) gains a Chart.js waveform/histogram chart, inline PDF preview, original `.TXT` download, and a review form with false-trigger flag + reviewer + notes.  `/admin/events` finally gets the modal too.  A new Settings field controls the mic chart's display unit.