Open the map out to the whole Milky Way

The map stopped at the catalogued 50 pc around the Sun — 0.33% of the
Galaxy's width — and looked like a point cloud with a search box.

Adds the galactic scale above it and the heads-up display the reference
map is built from.

The Galaxy is not a third coordinate space. It is the same parsec space
four orders of magnitude further out, so the model and the star field
crossfade against camera distance instead of switching, and the Sun stays
where it really is: 8.18 kpc out, on the Orion Spur, between the
Sagittarius and Perseus arms. The depth range scales with that distance —
one fixed near/far pair cannot both fly into a star and hold the Galaxy.

The structure in shared/astro/galaxy.ts is measured: the directions of the
centre and the north galactic pole, which fix the disc's 63 degree tilt
against the celestial equator; the Sun's galactocentric distance; and a
radius, azimuth and pitch angle per arm. The particles scattered around it
are not, and cannot be — dust hides the disc, so no catalogue holds the
Galaxy's stars. The view says so, and the model fades out before the
camera reaches the 50 pc where the real stars are.

The rest is the look: polar grids lying in the galactic plane with drop
lines from the Sun's neighbours, a scale ladder, a readout panel, range,
reticle and frame brackets. Two things had to give way for it. The
deep-sky shell is the sky as seen from here, so it dissolves rather than
letting the camera fly through a wall of nebulae, and so does the skybox,
which is a photograph taken from inside the thing now being viewed from
outside. Labels are picked by screen separation rather than distance
alone: the Sun's fifteen nearest neighbours are all inside four parsecs
and printed as one unreadable clump.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01WaySiNst4HhDXBHnMy8p5G

.junie/plans/nasa-star-map.md

@@ -136,7 +136,10 @@ interface DeepSkyRecord {
 - `KeplerPropagator` (`shared/astro/kepler.ts`) — pure function(s) converting `OrbitalElements` + epoch → Cartesian position; independently unit-testable.
 - `BodyDetailSceneComponent` — separate route/component with its own dedicated scene for a close-up view of one selected body, plus an `InfoPanelComponent` showing its data.
 - `SearchComponent` — text search across `stars-index.json`, `bodies.json`, `exoplanets.json`; on match, dispatches a navigation action.
-- `NavigationStore` (Angular signals-based) — holds `viewLevel: 'galaxy' | 'system'`, `selectedStarId`, `selectedBodyId`; consumed by scene components and routed body-detail view.
+- `NavigationStore` (Angular signals-based) — holds `viewLevel: 'galactic' | 'galaxy' | 'system'`, `selectedStarId`, `selectedBodyId`; consumed by scene components and routed body-detail view.
+- `MilkyWayRenderer` / `milky-way-model.ts` — the Galaxy itself as an instanced particle cloud scattered around the structural model in `shared/astro/galaxy.ts`, crossfaded against the catalogued star field by camera distance.
+- `PolarGridPlane` / `TetherField` (`grid-plane.ts`) — the reference plane the map is read against: rings and spokes lying in the galactic plane, plus drop lines from stars to it.
+- `StarmapHudComponent` — the heads-up display: scale ladder, readout panel, range, reticle and frame.
 
 ### File Structure
 ```
@@ -280,4 +283,11 @@ Selecting a planet/moon/exoplanet opens a dedicated close-up scene with real dat
 Users can search by name and jump directly to the matching star, system, or body.
 - Implement `SearchComponent` querying `stars-index.json`, `bodies.json`, and `exoplanets.json` for name matches.
 - On selecting a search result, dispatch the appropriate `NavigationStore` update (galaxy star, system body, or exoplanet) and trigger the corresponding camera transition or route change.
-- Ensure consistent state across `GalaxySystemSceneComponent` and `BodyDetailSceneComponent` when navigation originates from search rather than in-scene clicks.
+- Ensure consistent state across `GalaxySystemSceneComponent` and `BodyDetailSceneComponent` when navigation originates from search rather than in-scene clicks.
+
+### ✓ Step 7: Add the galactic scale and the heads-up display
+The map opens out from the catalogued neighbourhood to the whole Milky Way, in the visual language of the reference.
+- Add `shared/astro/galaxy.ts`: the galactic↔equatorial rotation, the Sun's galactocentric position, and logarithmic-spiral parameters per arm.
+- Add `MilkyWayRenderer`, crossfaded against the star field by camera distance so the two scales share one continuous parsec space rather than being separate scenes.
+- Add the galactic and local grid planes, star tethers, and the HUD (scale ladder, readout panel, range, reticle, frame).
+- Label the Galaxy model as a model wherever it is shown: its skeleton is measured, its particles are not.