docs(planning): record v1.4.20.1 hotfix wave

New `.planning/phase-v1421-hotfix-report.md` summarises the six
fixes (Daily Briefing regenerate · Coach day-level snapshot · Coach
prompt update · streaming-bubble dedup · drawer header · sources rail
scope picker), the test-count delta (2026 → 2036 unit), the
token-budget impact of the day-level snapshot (~190 → ~3000 tokens
per full-scope turn), and a recommendation to ship as a v1.4.20.1
hotfix.

STATE.md grows a Phase F section + status block tracking the six
commits on develop. Includes prettier polish across the touched
coach surfaces (sources-rail, drawer, message-thread, snapshot,
chat route).

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

src/components/insights/coach-panel/__tests__/sources-rail.test.tsx

@@ -53,9 +53,8 @@ describe("<SourcesRail>", () => {
 
   it("renders a checkbox per row + a window selector trigger", () => {
     const html = render(<SourcesRail />);
-    const checkboxes = (
-      html.match(/data-slot="coach-sources-checkbox"/g) ?? []
-    ).length;
+    const checkboxes = (html.match(/data-slot="coach-sources-checkbox"/g) ?? [])
+      .length;
     expect(checkboxes).toBe(5);
     expect(html).toContain('data-slot="coach-sources-window-trigger"');
   });

src/components/insights/coach-panel/coach-drawer.tsx

@@ -258,10 +258,7 @@ export function CoachDrawer({
           }
           sourcesRail={
             sourcesRail ?? (
-              <SourcesRail
-                scope={scope}
-                onScopeChange={setScope}
-              />
+              <SourcesRail scope={scope} onScopeChange={setScope} />
             )
           }
           thread={

src/components/insights/coach-panel/message-thread.tsx

@@ -67,9 +67,7 @@ export function MessageThread({
     messages.some((m) => m.id === streaming.messageId);
   const streamingActive =
     !streamingPersisted &&
-    (!!streaming?.inProgress ||
-      !!streaming?.content ||
-      !!streaming?.errorCode);
+    (!!streaming?.inProgress || !!streaming?.content || !!streaming?.errorCode);
 
   // Track scroll position so we don't yank the viewport when the user
   // is browsing earlier turns.

src/components/insights/coach-panel/sources-rail.tsx

@@ -82,7 +82,10 @@ export interface SourcesRailProps {
    * the controls still render but stay read-only — keeps the legend
    * surface stable for callers that don't yet wire scope through.
    */
-  onScopeChange?: (next: { sources: CoachScopeSource[]; window: CoachScopeWindow }) => void;
+  onScopeChange?: (next: {
+    sources: CoachScopeSource[];
+    window: CoachScopeWindow;
+  }) => void;
 }
 
 interface SourceRow {