feat(ux): B3.5 + B3.14 — sparkline range picker + shutdown copy

B3.5: settings.sparklineRangeDays (added schema-only in B2b) now drives
the recentCompletions fetch via a reactive effect; new segmented control
in Settings → Tasks lets the user pick 7 / 28 / 90 days. Default 7.

B3.14: /shutdown "Open loops" header softened to "Still here", body
copy updated to remove pressure ("Just naming them helps — nothing to
do here"), truncation tail drops the count. The whole "Still here"
section is now gated by a fresh-start derived flag — when B3.1 lands
and writes reentryFreshStartUntil, this surface auto-suppresses.

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

src/lib/pages/SettingsPage.svelte

@@ -814,6 +814,33 @@
     }
   });
 
+  // B3.5 — sparkline range picker. SegmentedButton works on string
+  // options; settings.sparklineRangeDays is the integer 7 / 28 / 90.
+  // Mirror in both directions so changes from either side propagate.
+  let sparklineRangeLabel = $state(
+    settings.sparklineRangeDays === 90
+      ? "90 days"
+      : settings.sparklineRangeDays === 28
+        ? "28 days"
+        : "7 days",
+  );
+  $effect(() => {
+    const next = sparklineRangeLabel === "90 days" ? 90 : sparklineRangeLabel === "28 days" ? 28 : 7;
+    if (settings.sparklineRangeDays !== next) {
+      settings.sparklineRangeDays = next;
+    }
+  });
+  $effect(() => {
+    const label = settings.sparklineRangeDays === 90
+      ? "90 days"
+      : settings.sparklineRangeDays === 28
+        ? "28 days"
+        : "7 days";
+    if (sparklineRangeLabel !== label) {
+      sparklineRangeLabel = label;
+    }
+  });
+
   async function downloadModel(size) {
     downloadingModel = size;
     downloadProgress = 0;
@@ -1575,8 +1602,29 @@
             <Toggle
               bind:checked={settings.showMomentumSparkline}
               label="Show momentum sparkline"
-              description="A tiny chart of the last 7 days' completion counts, shown on the Tasks header. Never counts against you."
+              description="A tiny chart of recent completion counts, shown on the Tasks header. Never counts against you."
             />
+
+            <!-- B3.5 — sparkline range picker. The integer field
+                 settings.sparklineRangeDays drives the
+                 list_recent_completions_cmd days argument via a
+                 reactive effect in completionStats.svelte. The
+                 SegmentedButton component works on string options, so
+                 we marshal between display labels and the integer
+                 the rest of the system expects via a local mirror. -->
+            {#if settings.showMomentumSparkline}
+              <div class="mt-5 pl-1 animate-fade-in">
+                <p class="text-[10px] font-medium text-text-tertiary uppercase tracking-wider mb-2">Sparkline range</p>
+                <SegmentedButton
+                  options={["7 days", "28 days", "90 days"]}
+                  bind:value={sparklineRangeLabel}
+                  size="small"
+                />
+                <p class="text-[11px] text-text-tertiary mt-2">
+                  How far back the sparkline looks. Wider windows show longer-arc trends; the narrower window stays close to right-now.
+                </p>
+              </div>
+            {/if}
           </div>
         {/if}
       </div>