Keep a place, and come back to it

Restores the commit reverted off the routing branch, which is where it was
committed by mistake. The change is unmodified; only its branch is.

The map had no memory. Every visit started at the same overview, and a system
worth returning to had to be found again by name each time. A mark on the
readout and on a body's panel now keeps it, a Bookmarks tab lists what has been
kept, and choosing one goes there — a star by flying into its system, a body by
opening its page.

Local storage, not an account. This map asks nobody to sign in, and a list of
stars somebody liked is not worth a server. Every read of that store is
defensive, because it is a string a person can edit, another tab can write, and
a browser can refuse to hand over at all: a bad entry is skipped rather than
losing the rest, duplicates are collapsed since two entries for one place would
each toggle the other's control, the list is bounded so a hand-edited store
cannot decide how much this renders, and where storage is denied outright the
bookmarks still work for the visit — they just do not outlive it.

The name is stored alongside the id rather than looked up, so the list reads
before the catalogues have loaded, and a bookmark to something a later
catalogue no longer holds still says what it was instead of decaying into a
bare number.

The tab is offered even when it is empty, and says what the mark does: a tab
that appears only once you have already found the feature is a tab that never
taught anyone anything.

Choosing a kept place hands the panel back to the readout, the same move as
choosing a search result and for the same reason. That behaviour is what the
end-to-end spec caught missing — the readout it asserted on did not exist,
because the panel just used was still covering it.

Verified: build clean, 587/587 unit, 11/11 end-to-end, design detector clean,
screenshots at 1440x900 and 390x844.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016jxMkwA2rbicdGxHosecYi

src/app/features/body-detail/body-detail-scene.component.ts

@@ -1,5 +1,5 @@
 import { AfterViewInit, Component, ElementRef, OnDestroy, signal, viewChild } from '@angular/core';
-import { ActivatedRoute, RouterLink } from '@angular/router';
+import { ActivatedRoute, Router, RouterLink } from '@angular/router';
 import { Subscription } from 'rxjs';
 import * as THREE from 'three/webgpu';
 import { OrbitControls } from 'three/addons/controls/OrbitControls.js';
@@ -12,6 +12,7 @@ import { atmosphereColorFor, bodyTexturePath, loadCachedTexture, MILKY_WAY_SKYBO
 import { BodyRecord } from '../../shared/models/body.model';
 import { ExoplanetRecord } from '../../shared/models/exoplanet.model';
 import { StarRecord } from '../../shared/models/star.model';
+import { Bookmark } from '../../shared/state/bookmarks.store';
 import { NavigationStore } from '../../shared/state/navigation.store';
 import { ChevronIconComponent } from '../../shared/ui/chevron-icon.component';
 import { HudDockComponent } from '../hud/hud-dock.component';
@@ -57,12 +58,23 @@ const GLOW_SCALE = 2.6;
           </a>
         </div>
       }
-      <!-- Search only: there is no scene readout here, the info panel is the reading. -->
-      <app-hud-dock />
+      <!-- Search and what has been kept: there is no scene readout here, the info panel is
+           the reading, and the panel's own control is what keeps this body. -->
+      <app-hud-dock (bookmarkChosen)="goToBookmark($event)" />
     </div>
   `
 })
 export class BodyDetailSceneComponent implements AfterViewInit, OnDestroy {
+  /** A kept place, revisited from this page: a star means leaving it for the map. */
+  goToBookmark(bookmark: Bookmark): void {
+    if (bookmark.kind === 'star') {
+      this.navigationStore.selectStar(Number(bookmark.id));
+      void this.router.navigate(['/']);
+    } else {
+      void this.router.navigate(['/body', String(bookmark.id)]);
+    }
+  }
+
   private readonly canvasRef = viewChild.required<ElementRef<HTMLCanvasElement>>('canvas');
 
   private controls?: OrbitControls;
@@ -87,6 +99,7 @@ export class BodyDetailSceneComponent implements AfterViewInit, OnDestroy {
     private readonly engine: EngineService,
     private readonly dataLoader: DataLoaderService,
     private readonly route: ActivatedRoute,
+    private readonly router: Router,
     private readonly navigationStore: NavigationStore
   ) {}