fix(ui): align 'this week' to upcoming Monday (Sprint 7)

User report 2026-06-05: 'webui Meal Planner page is empty' on Friday
morning after the Friday email went out. Root cause: the orchestrator
keyed plans by the most-recent-Friday while the frontend's isoMonday()
returned the most-recent-Monday — a 7-day mismatch on Fridays.

Fixes (one semantic across the stack):
- runner._current_week_start() returns the upcoming Monday (today if
  Mon, else the next Mon). The Friday email subject
  ('Meal plan for week of <date>') automatically picks up the new
  value via run.week_start_date.
- frontend isoMonday -> upcomingMonday (same logic; renamed for
  intent). isoMonday kept as a deprecated alias.
- New WeekRangeNav component (Dashboard + ShoppingList share it).
  Renders [<]  Jun 8 - Jun 14  [>] with clickable chevrons and a
  clickable range label that jumps to the upcoming week. Replaces
  the Sprint 5 inline segmented control on both pages.
- New formatWeekRange(mondayIso) helper (UTC-stable; uses
  timeZone: 'UTC' so the rendered date matches the stored ISO date
  regardless of viewer TZ; closes a latent bug in formatIsoDate too).
- New SQL fix script that retargets the user's 3-pending-items plan
  from 2026-06-05 (Friday-keyed) to 2026-06-08 (upcoming Monday).
  Idempotent + transaction-wrapped. Optional block for 2026-05-29.

No backend migration. No new dependencies. Deploy is git pull +
run the SQL fix + docker compose up -d --build backend frontend.
See Review/sprint7-verification.md for the full deploy + smoke flow.

Files:
- backend/app/services/orchestrator/runner.py:20-35
- backend/scripts/fix_2026_06_05_to_2026_06_08.sql (new)
- frontend/src/lib/utils.ts:43-130
- frontend/src/components/WeekRangeNav.tsx (new)
- frontend/src/pages/Dashboard.tsx (3 call sites + 1 segmented control)
- frontend/src/pages/ShoppingList.tsx (5 call sites + 2 segmented controls)
- Review/{sprint7-verification,ui-nielsen-audit,handoff-ui-audit}.md
- fix-ui-audit.md
- docs/HANDOFF.md
- .agent/{plan,context}.md

Review/handoff-ui-audit.md

@@ -2,7 +2,21 @@
 
 You are taking over a 6-sprint UI/UX audit and fix cycle. All code changes are committed and build green. The user's deployment host (Tailscale `100.108.224.12`) is the only environment you should touch for verification — the local repo on this machine (`/home/peter/Projects/MealPlanner`) was the editing host; the running app lives elsewhere.
 
-**Date of handoff: 2026-06-04.**
+**Date of handoff: 2026-06-04. Last updated: 2026-06-05 (Sprint 7 in progress).**
+
+---
+
+## ⚠️ Active sprint: Sprint 7 — Fix webui "empty meal plan" (date-semantics mismatch)
+
+**Status: in progress. User approved on 2026-06-05. Code not yet written.**
+
+**Root cause (one-liner):** the orchestrator plans the **upcoming** Mon-Sun week (Fri 2026-06-05 → key 2026-06-08), but the frontend `isoMonday()` returns the **current** Mon-Sun (Fri 2026-06-05 → 2026-06-01). Email + DB + webui disagree by 7 days. User sees an empty page.
+
+**Scope (7 boxes):** see `.agent/plan.md` "Active sprint" section. Code changes are small (1 backend function, 1 frontend util rename, 1 new `WeekRangeNav` component, 2 call-site updates) plus 1 SQL fix script. **No migration.**
+
+**Tracking docs:** `Review/sprint7-verification.md` (deploy + smoke), `Review/ui-nielsen-audit.md` Sprint 7 status block, `fix-ui-audit.md` S7.1–S7.6, `docs/HANDOFF.md` Sprint 7 section. All will be filled in before the user pulls.
+
+**Thread 2 + Thread 3 are deferred** (cross-week "rejected" semantics + §Future backlog) until S7 is deployed + verified.
 
 ---
 
@@ -264,4 +278,4 @@ cd frontend && npm run build
 
 Trust the build output. Trust the smoke checklist. Don't trust the deployment host's UI until the user confirms. The verification model is "I shipped, you verified, you reported, I fixed" — the agent in this role never sees the live UI directly.
 
-**Last updated: 2026-06-03** — Sprints 1, 2, 3 all committed; Sprint 1 deployed; Sprints 2 and 3 awaiting deploy.
+**Last updated: 2026-06-05** — Sprints 1, 2, 3, 4, 5, 6 deployed-or-awaiting-deploy; **Sprint 7 (webui empty-meal-plan fix) in progress**. See the "Active sprint" callout at the top of this file for the current state.