Let the Routes panel be clicked as soon as it is back, and stop it departing from elsewhere

From the review of #24. Two defects, both in a real browser.

The panel keeps its entries across a trip to another tab, but still replayed the acquire wipe on
the way back, and for the 380 ms that runs, its clip path swallows clicks: type "Siri", leave for
Readout, come back and click the Sirius suggestion, and the click lands on the star field behind
it — measured, the element under the pointer is the canvas, and the field stays "Siri". The wipe is
gone from this one panel: it is not acquiring anything it did not already have.

The departure field fell back to the star the view is in whenever nothing had been chosen, text in
the field or not. So a field reading "Sol" that was never resolved plotted from Barnard's Star:
"1 Barnard's Star, 2 Sol, 3 Sirius", the panel naming one departure and the route leaving from
another. Text nobody chose is no longer a departure, and the button waits until it is one or the
field is empty again.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016jxMkwA2rbicdGxHosecYi

src/app/features/hud/hud-dock.component.spec.ts

@@ -253,6 +253,50 @@ describe('HudDockComponent', () => {
     expect(tab('Readout').getAttribute('aria-selected')).toBe('true');
   });
 
+  it('will not plot from a departure that was typed but never chosen', () => {
+    setReadout();
+    fixture.componentRef.setInput('routing', true);
+    fixture.componentRef.setInput('currentStar', { id: 3, name: "Barnard's Star", subtitle: '1.8 pc' });
+    fixture.componentRef.setInput('routeOptions', [{ id: 7, name: 'Sirius', subtitle: '2.6 pc' }]);
+    fixture.componentRef.setInput('defaultTab', 'routes');
+    fixture.detectChanges();
+    const plot = () => [...host().querySelectorAll<HTMLButtonElement>('button')].find((button) => button.textContent?.includes('Plot route'))!;
+    const type = (field: string, value: string) => {
+      const input = host().querySelector<HTMLInputElement>(`#route-${field}`)!;
+      input.value = value;
+      input.dispatchEvent(new Event('input'));
+      fixture.detectChanges();
+    };
+
+    type('to', 'Sir');
+    host().querySelector<HTMLButtonElement>('#dock-panel-routes ul button')!.click();
+    fixture.detectChanges();
+    // With the departure field empty, the view's own star stands in for it.
+    expect(plot().disabled).toBe(false);
+
+    // Text that names no chosen star is not a departure: plotting from the view's star instead
+    // would name one place and leave from another.
+    type('from', 'Sol');
+    expect(plot().disabled).toBe(true);
+
+    type('from', '');
+    expect(plot().disabled).toBe(false);
+  });
+
+  it('does not replay the acquire wipe over the Routes panel, whose entries survive the trip', () => {
+    setReadout();
+    fixture.componentRef.setInput('routing', true);
+    fixture.componentRef.setInput('display', DEFAULT_HUD_DISPLAY);
+    fixture.componentRef.setInput('defaultTab', 'routes');
+    fixture.detectChanges();
+
+    // The wipe clips its panel for 380 ms, which swallows clicks on entries that are already there.
+    expect(host().querySelector('#dock-panel-routes')?.classList.contains('hud-acquire')).toBe(false);
+    tab('Display').click();
+    fixture.detectChanges();
+    expect(host().querySelector('#dock-panel-display')?.classList.contains('hud-acquire')).toBe(true);
+  });
+
   it('keeps what the Routes panel was set to across a trip to another tab', () => {
     setReadout();
     fixture.componentRef.setInput('routing', true);

src/app/features/hud/hud-dock.component.ts

@@ -186,9 +186,11 @@ function isWideViewport(): boolean {
       }
       <!-- Hidden rather than unmounted: the departure, destination and range it holds would
            otherwise reset on every trip to another tab, while the scene kept drawing the graph at
-           the old range. Hiding still replays the acquire wipe when it is shown again. -->
+           the old range. No acquire wipe, unlike the panels around it: this is the one that comes
+           back with what it had, so it is not acquiring anything — and for the 380 ms the wipe
+           runs, its clip path swallows clicks on the suggestions it just brought back. -->
       @if (routing()) {
-        <section id="dock-panel-routes" role="tabpanel" aria-labelledby="dock-tab-routes" [hidden]="activeTab() !== 'routes'" class="hud-acquire hud-brackets hud-surface pointer-events-auto mb-2 w-full max-w-xl px-4 py-3">
+        <section id="dock-panel-routes" role="tabpanel" aria-labelledby="dock-tab-routes" [hidden]="activeTab() !== 'routes'" class="hud-brackets hud-surface pointer-events-auto mb-2 w-full max-w-xl px-4 py-3">
           <app-routes-panel
             [result]="routeResult()"
             [pending]="routePending()"

src/app/features/hud/routes-panel.component.ts

@@ -176,8 +176,12 @@ export class RoutesPanelComponent {
   private readonly chosen = signal<Record<Field, RouteStarOption | null>>({ from: null, to: null });
   private readonly typed = signal<Record<Field, string>>({ from: '', to: '' });
 
-  /** Departure falls back to wherever the view already is, so one field is usually enough. */
+  /**
-  private readonly departure = computed(() => this.chosen().from ?? this.currentStar());
+   * Departure falls back to wherever the view already is, so one field is usually enough — but only
+   * while the field is empty. Text left in it that names no chosen star used to fall back all the
+   * same, so the panel read "Sol" and the route left from whatever the view had since flown to.
+   */
+  private readonly departure = computed(() => this.chosen().from ?? (this.typed().from ? null : this.currentStar()));
 
   readonly canPlot = computed(() => this.departure() !== null && this.chosen().to !== null);
   readonly rangeLabel = computed(() => formatParsecs(this.rangePc()));