feat(gameplay): add starting base module and refine galaxy/character creation systems

Co-Authored-By: Oz <oz-agent@warp.dev>

apps/game/src/gameplay/starting_base/mod.rs

@@ -0,0 +1,89 @@
+//! Starting base selection scene.
+//!
+//! After character creation, the player chooses a starting base from generated
+//! outer-galaxy systems. The choice is kept in a resource until persistence is
+//! wired into the game client.
+
+mod scene;
+mod ui;
+
+use bevy::prelude::*;
+
+use crate::gameplay::galaxy::StartingBaseCandidate;
+use crate::state::AppState;
+
+pub struct StartingBasePlugin;
+
+impl Plugin for StartingBasePlugin {
+    fn build(&self, app: &mut App) {
+        app.init_resource::<StartingBaseDraft>()
+            .add_systems(
+                OnEnter(AppState::StartingBaseSelection),
+                (scene::setup_starting_base_scene, ui::setup_starting_base_ui).chain(),
+            )
+            .add_systems(
+                OnExit(AppState::StartingBaseSelection),
+                despawn_starting_base_ui,
+            )
+            .add_systems(
+                Update,
+                (
+                    escape_to_character_creation,
+                    scene::starting_base_orbit_camera_control,
+                    scene::select_starting_base_on_click,
+                    scene::animate_starting_base_selection,
+                    ui::scroll_starting_base_panels,
+                    ui::candidate_button_handler,
+                    ui::refresh_starting_base_ui,
+                    ui::action_button_handler,
+                )
+                    .chain()
+                    .run_if(in_state(AppState::StartingBaseSelection)),
+            );
+    }
+}
+
+#[derive(Resource, Default)]
+pub struct StartingBaseDraft {
+    pub candidates: Vec<StartingBaseCandidate>,
+    pub selected_index: Option<usize>,
+}
+
+#[derive(Resource, Debug, Clone)]
+pub struct StartingBaseSelection {
+    pub system_id: String,
+    pub system_name: String,
+    pub faction: &'static str,
+    pub security: f32,
+}
+
+#[derive(Component)]
+pub struct StartingBaseSpawned;
+
+#[derive(Component)]
+pub struct StartingBaseInputBlocker;
+
+#[derive(Component, Clone, Copy)]
+pub enum StartingBaseButton {
+    Candidate(usize),
+    Confirm,
+    Back,
+}
+
+fn despawn_starting_base_ui(
+    mut commands: Commands,
+    query: Query<Entity, With<StartingBaseSpawned>>,
+) {
+    for entity in &query {
+        commands.entity(entity).despawn();
+    }
+}
+
+fn escape_to_character_creation(
+    keys: Res<ButtonInput<KeyCode>>,
+    mut next_state: ResMut<NextState<AppState>>,
+) {
+    if keys.just_pressed(KeyCode::Escape) {
+        next_state.set(AppState::CharacterCreation);
+    }
+}