docs: changelog [Unreleased] — add the client portal feature

Documents the read-only client portal under [Unreleased] alongside the SLM
live-monitoring work: per-client scoping + interim auth, live location view with
the auto-closing WS stream, locations overview map + rollup, the alerts
config→surface→24/7 track, operator sharing tools, the field-instrument design +
light/dark toggle, the security posture, and upgrade notes (migration, SECRET_KEY,
SLMM alert-engine pairing).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

CHANGELOG.md

@@ -49,6 +49,62 @@ The two builds must ship **together**.  Note the `docker-compose.yml` container
 
 ---
 
+### Client portal *(new — read-only client-facing view)*
+
+A scoped, read-only portal at **`/portal/*`** where a client sees only *their*
+locations, live.  Built inside Terra-View (no new service), reusing the cached
+SLMM feed; every route resolves the client through one swappable
+`get_current_client` gate, so the interim magic/open-link auth can be replaced
+(M4) without touching routes or templates.  Strictly read-only — no device control.
+
+#### Added
+
+- **Per-client scoping + interim auth.**  New `Client`, `ClientAccessToken`, and a
+  `Project.client_id` FK.  A signed (HMAC) session cookie carries the access-token
+  id, re-validated against the DB each request (revoke kills live sessions, with
+  server-side expiry).  Entry via a magic link (`/portal/enter/{token}`) or a
+  dev-only plain link (`/portal/open/{id}`, `PORTAL_OPEN_LINKS`, **default off**).
+- **Live location view.**  KPI cards (Lp/Leq/Lmax/L1/L10) + chart populate
+  instantly from cache, then upgrade to a real **~1 Hz WebSocket stream** scoped to
+  the client's unit (a scrubbed bridge to the SLMM fan-out feed).  The stream
+  **auto-closes when the tab is hidden** (Page Visibility) and after a 15-min idle
+  cap, so an abandoned tab can't pin the device at 1 Hz / burn cellular.
+- **Locations overview.**  Live status map (level-colored dots, dark/light CARTO
+  tiles) + a status rollup (live/offline counts, "loudest now").  Leq is the
+  headline metric.
+- **Alerts (config → surface → 24/7).**  Threshold-rule config on the SLM detail
+  page (proxying SLMM's alert CRUD); breach **history + ack** internally and a
+  read-only, scrubbed history + current-alarm banner + **"your alert limits"** panel
+  in the portal; enabling a rule pins that device's monitor on so alerts evaluate
+  round-the-clock.
+- **Operator sharing tools.**  A **"View client portal"** preview button and a
+  **"Copy client link"** modal (mint / list / revoke magic links) on the project
+  page, plus a `backend/portal_admin.py` CLI.
+- **Field-instrument design.**  Distinctive themed portal — Hanken Grotesk UI +
+  IBM Plex Mono readouts, panel system, pulsing live dot, staggered reveal — with a
+  **light/dark toggle** (light default, persisted, no-flash).
+
+#### Security
+
+- All scoping enforced server-side (404-not-403, no existence leak); client
+  endpoints return **scrubbed** projections (no device-health/internal ids); WS
+  frames whitelisted; operator-set strings HTML-escaped before injection (XSS).
+  Pre-merge code review hardened cookie expiry, open-links default, and the slug
+  collision.  Remaining hardening (reverse proxy, TLS, `SECRET_KEY`, M4 auth) is
+  tracked in `docs/CLIENT_PORTAL.md` → "Security hardening backlog".
+
+#### Upgrade Notes
+
+- **Migration:** `docker compose exec web-app python3 backend/migrate_add_client_portal.py`
+  (adds `projects.client_id`; the `clients` / `client_access_tokens` tables
+  auto-create).
+- Set a real **`SECRET_KEY`** in any internet-facing env (signs session cookies),
+  and keep **`PORTAL_OPEN_LINKS=false`** there.
+- Portal alerts depend on the **SLMM `dev`** alert engine (rules/events/evaluator +
+  cooldown + keepalive coupling) — same build pairing as above.
+
+---
+
 ## [0.13.3] - 2026-06-05
 
 Calibration sync from SFM events.  Closes the manual data-entry loop on calibration dates — Terra-View now pulls `device.calibration_date` from each seismograph's most recent event sidecar once a day and updates `RosterUnit.last_calibrated` when the device reports something fresher than what's stored.  Manual edits still win when they're newer than the latest event; a fresh event arriving later supersedes the manual edit.  Adds a "Sync now" button under Settings → Advanced → Calibration Defaults for on-demand runs, and a `docs/ROADMAP.md` to track in-flight + deferred work.