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/galaxy-system/galaxy-system-scene.component.ts

@@ -13,6 +13,7 @@ import { ExoplanetRecord } from '../../shared/models/exoplanet.model';
 import { applyMilkyWaySkybox, createGlowSprite } from '../../shared/rendering/skybox';
 import { loadCachedTexture, MILKY_WAY_SKYBOX_PATH, SUN_TEXTURE_PATH } from '../../shared/rendering/texture-catalog';
 import { StarRecord } from '../../shared/models/star.model';
+import { Bookmark } from '../../shared/state/bookmarks.store';
 import { NavigationStore, ViewLevel } from '../../shared/state/navigation.store';
 import { CameraRigController } from './camera-rig-controller';
 import { DeepSkyRenderer } from './deep-sky-renderer';
@@ -225,12 +226,14 @@ function galacticOverviewPose(): { position: THREE.Vector3; target: THREE.Vector
         [routeResult]="routeResult()"
         [routeOptions]="routeOptions()"
         [currentStar]="currentStarOption()"
+        [keepableStarId]="navigationStore.selectedStarId()"
         defaultTab="readout"
         (displayChange)="display.set($event)"
         (routeQuery)="onRouteQuery($event)"
         (routeRequested)="onRouteRequested($event)"
         (routeStarSelected)="navigationStore.selectStar($event)"
         (jumpRangeChange)="jumpRangePc.set($event)"
+        (bookmarkChosen)="goToBookmark($event)"
       />
     </div>
   `
@@ -1204,6 +1207,15 @@ export class GalaxySystemSceneComponent implements AfterViewInit, OnDestroy {
     this.clearObjectCard();
   }
 
+  /** A kept place, revisited: a star is a system to fly into, a body is a page to open. */
+  goToBookmark(bookmark: Bookmark): void {
+    if (bookmark.kind === 'star') {
+      this.navigationStore.selectStar(Number(bookmark.id));
+    } else {
+      this.openObjectDetail(String(bookmark.id));
+    }
+  }
+
   /** The deliberate step out to the dedicated route, from the card's own control. */
   openObjectDetail(id: string): void {
     this.navigationStore.selectBody(id);