feat: one page for a category, tag, budget or merchant

The page answers how much and whether that is normal: this month per
currency with count, median and pace against a typical month, thirteen
months as lanes per currency, and what is inside (merchants, cards,
budgets, tags, subtags) on 1 to 4 with Enter narrowing the transactions
below. Budgets keep spent, left and overspent with the limit line;
expense and revenue accounts use the same page with visits and cadence.
The twelve period cards and per-day charts are gone.

src/lib/components/dimension/Merchant.svelte

@@ -0,0 +1,90 @@
+<script lang="ts">
+  import { daysBetween } from "#lib/dates.js";
+  import { DimensionModel } from "#lib/dimension/model.svelte.js";
+  import { merchantSpec } from "#lib/dimension/spec.js";
+  import { counted, factsOf, fmt } from "#lib/dimension/stats.js";
+  import { formatDate, formatNumber } from "#lib/format.js";
+  import Dimension from "./Dimension.svelte";
+
+  let { id, everything = false }: { id: string; everything?: boolean } =
+    $props();
+
+  const model = new DimensionModel(() => ({
+    allTime: true,
+    everything,
+    spec: merchantSpec(id),
+  }));
+
+  const history = $derived(
+    factsOf(
+      model.main.filter((flow) => flow.date <= model.now),
+      model.codes
+    )
+  );
+  const noun = $derived(model.dir === -1 ? "visits" : "payments");
+  const every = $derived(
+    history.count > 1
+      ? daysBetween(history.first, history.last) / (history.count - 1)
+      : null
+  );
+  const bill = $derived(model.main.find((flow) => flow.bill)?.bill ?? null);
+</script>
+
+{#snippet lead()}
+  {#if !model.loading}
+    <p
+      class="flex flex-wrap items-baseline gap-x-1.5 gap-y-0.5 text-[14px] text-cladd-fg-soft"
+    >
+      {#if history.count > 0}
+        {#each history.sums as sum, i (sum.code)}
+          {#if i > 0}
+            <span>+</span>
+          {/if}
+          <span class="num font-semibold text-[22px] text-cladd-fg"
+            >{fmt(sum.code, sum.amount, 0)}</span
+          >
+        {/each}
+        <span>all time · {counted(history.count, noun)}</span>
+        {#if history.median}
+          <span
+            >· median
+            <span class="num text-cladd-fg"
+              >{fmt(history.median.code, history.median.amount, 0)}</span
+            ></span
+          >
+        {/if}
+        {#if every !== null}
+          <span
+            >· every
+            <span class="num text-cladd-fg"
+              >{formatNumber(every, every < 10 ? 1 : 0)}</span
+            >
+            days</span
+          >
+        {/if}
+        <span
+          >· last
+          <span class="text-cladd-fg"
+            >{formatDate(history.last, "short")}</span
+          ></span
+        >
+        {#if bill}
+          <span
+            >· subscription
+            <a
+              class="text-brand hover:underline"
+              href="/subscriptions/show/{bill.id}"
+              >{bill.name}</a
+            ></span
+          >
+        {/if}
+      {:else}
+        <span class="font-semibold text-[22px] text-cladd-fg"
+          >No {noun} yet</span
+        >
+      {/if}
+    </p>
+  {/if}
+{/snippet}
+
+<Dimension accountId={id} {lead} {model} {noun} />