Phase 7: telemetry and usage (daily rollup + week dashboard)

Build on Phases 1–6. Telemetry already arrived on
restrict/<device>/telemetry; this phase stores it in a daily rollup and
shows it.

- store: migration 003 adds telemetry_daily (device, day, app seconds,
  site seconds). InsertTelemetry maintains the affected days in the same
  transaction; RebuildRollups backfills and repairs it. UsageRange and
  TopUsage serve the week grid and top lists. CapAudit enforces the
  size-capped append-only audit log from AGENTS.md §7.
- web: GET /devices/{id}/usage — Monday-to-Sunday totals plus the top 10
  apps and top 10 sites, using CSP-safe native <progress> bars.
- theme.js: light/dark from the OS preference, with a nav toggle, loaded
  as an external script so the strict CSP still holds.
- cmd/control: `rollup` subcommand; rollup rebuild and audit cap at
  start-up and every 15 minutes.
- Version 0.5.0-phase7 (compose, Makefile, docs).

Tests: go test ./... and go vet ./... pass in golang:1.25-alpine.

Co-Authored-By: Paperclip <noreply@paperclip.ing>

internal/web/usage_test.go

@@ -0,0 +1,94 @@
+package web
+
+import (
+	"fmt"
+	"net/http"
+	"strings"
+	"testing"
+	"time"
+
+	"gitea.lab.audasmedia.com.au/sam/internet_use_control/internal/store"
+)
+
+func TestUsageScreenShowsAWeek(t *testing.T) {
+	app := newTestApp(t)
+	dev := createTestDevice(t, app)
+	ctx := t.Context()
+
+	// Seed the whole current week: apps and domains for every day.
+	start := weekStart(time.Now())
+	for i := 0; i < 7; i++ {
+		day := start.AddDate(0, 0, i).Format("2006-01-02")
+		if _, err := app.store.InsertTelemetry(ctx, dev.ID, day, []store.TelemetryEntry{
+			{App: "com.roblox.client", Seconds: (i + 1) * 600},
+			{App: "com.spotify.music", Seconds: 300},
+			{Domain: "roblox.com", Seconds: (i + 1) * 600},
+		}); err != nil {
+			t.Fatalf("InsertTelemetry %s: %v", day, err)
+		}
+	}
+
+	rec := app.do(t, http.MethodGet, fmt.Sprintf("/devices/%d/usage", dev.ID), nil)
+	if rec.Code != http.StatusOK {
+		t.Fatalf("GET usage = %d, want 200; body=%s", rec.Code, rec.Body.String())
+	}
+	body := rec.Body.String()
+	for _, want := range []string{
+		"Usage", "Top apps", "Top sites", "App time", "Site time",
+		"com.roblox.client", "com.spotify.music", "roblox.com",
+		fmt.Sprintf("%d", dev.ID), "Harry&#39;s Pixel",
+	} {
+		if !strings.Contains(body, want) {
+			t.Errorf("usage page missing %q", want)
+		}
+	}
+	// Seven day rows: the weekday abbreviations must all be present.
+	for _, wd := range []string{"Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun"} {
+		if !strings.Contains(body, ">"+wd+" <") {
+			t.Errorf("usage page missing the %s row", wd)
+		}
+	}
+
+	// A week with no data renders the empty state, never an error.
+	rec = app.do(t, http.MethodGet,
+		fmt.Sprintf("/devices/%d/usage?week=2020-01-01", dev.ID), nil)
+	if rec.Code != http.StatusOK || !strings.Contains(rec.Body.String(), "No usage for this week") {
+		t.Errorf("empty week = %d, want the empty state", rec.Code)
+	}
+}
+
+func TestWeekHelpers(t *testing.T) {
+	loc := time.UTC
+	// A Sunday belongs to the week that started the previous Monday.
+	sunday := time.Date(2026, 10, 18, 12, 0, 0, 0, loc) // Sunday
+	got := weekStart(sunday)
+	want := time.Date(2026, 10, 12, 0, 0, 0, 0, loc)
+	if !got.Equal(want) {
+		t.Errorf("weekStart(Sun) = %s, want %s", got, want)
+	}
+
+	// A bad ?week= value falls back to now instead of failing.
+	now := time.Date(2026, 10, 15, 9, 0, 0, 0, loc)
+	if got := parseWeekAnchor("not-a-date", now); !got.Equal(now) {
+		t.Errorf("parseWeekAnchor(bad) = %s, want now", got)
+	}
+	if got := parseWeekAnchor("2026-10-12", now); got.Day() != 12 || got.Month() != time.October {
+		t.Errorf("parseWeekAnchor(valid) = %s", got)
+	}
+
+	if got := formatSeconds(0); got != "0m" {
+		t.Errorf("formatSeconds(0) = %q", got)
+	}
+	if got := formatSeconds(3600); got != "1h 00m" {
+		t.Errorf("formatSeconds(3600) = %q", got)
+	}
+	if got := formatSeconds(30); got != "under a minute" {
+		t.Errorf("formatSeconds(30) = %q", got)
+	}
+	if got := percent(50, 100); got != 50 {
+		t.Errorf("percent(50,100) = %d", got)
+	}
+	if got := percent(50, 0); got != 0 {
+		t.Errorf("percent with max 0 = %d, want 0", got)
+	}
+}