fix(ui): F8-10 owner-feedback — persistent filters, camera, disabled visual, dropdown narrowing (#53)

Polish pass after the first F8-10 walkthrough:

  - table-planets: moved the `foreign` chip to the end of the row and
    hid the race dropdown until `foreign` is on (it never made sense
    to pick a race while the bucket itself was off).
  - persistent per-table filter / sort state — extracted to
    `table-{planets,ship-groups,fleets}-state.svelte.ts` singletons so
    a row click → map → back to the table restores the prior chip /
    dropdown / sort state. Held in memory only; an F5 still resets.
  - table-ship-groups: the planet and class dropdowns now narrow to
    the slice surviving the owner checkboxes, so toggling `foreign`
    off removes planets / classes touched only by foreign rows.
  - map.svelte: camera (centre + zoom) is captured on every dispose
    path into a new `GameStateStore.lastCamera` and consumed on the
    next mount, so leaving the map for any other active view and
    coming back restores the prior pan / zoom. A pending focus from
    the tables still wins for the centre point.
  - table-ship-classes: `:disabled` now reads as disabled (muted
    colour, no hover ring, not-allowed cursor) — the click was already
    a no-op, only the visual was lying.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

ui/frontend/src/lib/active-view/table-ship-classes.svelte

@@ -359,7 +359,12 @@ data fetching is performed here — the layout is responsible.
 		border-radius: 3px;
 		cursor: pointer;
 	}
-	.delete:hover {
+	.delete:not(:disabled):hover {
 		border-color: var(--color-danger);
 	}
+	.delete:disabled {
+		cursor: not-allowed;
+		color: var(--color-text-muted);
+		opacity: 0.55;
+	}
 </style>