Make adressables great again #1494

[rohitkulkarni97]

Summary

This PR replaces the legacy static Assets lookup/database bootstrap with a scene-owned, async asset system built around GUIDs, catalogs, backend loaders, and disposable asset handles. The configured content path now routes the main SS3D asset databases through Addressables, while the provider/lifecycle layer keeps loaded assets resident only while handles or spawned instances still reference them.

It also adds the FishNet-side support required for addressable network prefabs: deterministic GUID-based prefab IDs, runtime registration of loaded addressable prefabs, synchronized client preloading before spawn, and late-join gating so clients do not observe addressable objects before the required prefabs are loaded.

PR checklist

• The game builds properly without errors.
• No unrelated changes are present.
• No "trash" files are committed.
• Relevant code is documented.
• Update the related GitBook document, or create a new one if needed.

Testing

Automated coverage added/updated:

• Edit Mode tests for AssetHandle, AssetProvider, AssetLifecycleTracker, InstanceLifetimeTracker, and NetworkObjectsGenerator.
• Play Mode tests for asset lifecycle/instance lifetime integration.
• Asset audit tests for catalog/database inclusion, non-null database GUIDs, and prefab stamping validation.
• FakeAssetBackend and test assembly access for exercising the internal asset loading flow.

Manual validation still needed:

• Full Unity build.
• Host, server, and client smoke tests for item spawn, crafting, tile placement/loading, role loadout spawn, audio playback, and interaction icons.
• Network spawn paths for addressable prefabs, including late-joining clients.

Networking checklist

• Works from host in host mode.
• Works from server in server mode.
• Works on server in client mode.
• Works and is synchronized across different clients.
• Is persistent.

Changes

Asset System

• Added AssetSubSystem as the startup-owned composition root for asset catalogs, backend initialization, database lookup, load/unload event relays, and the network preload barrier.
• Added AssetRequest<T> and AssetHandle<T> as the new async loading API. Handles are ref-counted and disposable; helper guards can tie handle lifetime to Unity objects.
• Added AssetProvider, AssetLifecycleTracker, and InstanceLifetimeTracker to dedupe concurrent loads, track handles and instantiated prefab copies, and unload assets when the last reference is released.
• Added backend abstraction with IAssetBackend, AddressablesBackend, ResourcesBackend, and AssetBackendType.
• Removed the old static Assets lookup flow and the separate AssetsInitializationTrigger.

Catalogs And Databases

• Reworked asset databases into backend-aware AssetCatalog/AssetDatabase assets.
• Added an AddressablesCatalog containing the seven configured databases: CraftingRecipes, InteractionIcons, Items, Materials, ParticlesEffects, Sounds, and WorldSpaceUI.
• Moved database assets under Assets/Content/Data/AssetSystem/Databases.
• Simplified ObjectAssetReference so references store the asset GUID only, rather than GUID plus database ID.
• Updated editor inspectors, database code generation, and object reference generation to work from catalog/database GUIDs and to stamp prefabs during generation.

Networked Addressables

• Added NetworkBarrier and PreloadCondition to coordinate loading addressable prefabs across server and clients.
• Added NetworkSpawner overloads for spawning by ObjectAssetReference, GUID, GameObject, NetworkObject, or NetworkBehaviour while ensuring clients are ready before FishNet spawns.
• Replaced FishNet's direct prefab collection flow with a generated NetworkObjects asset keyed by deterministic GUID order.
• Added NetworkObjectsGenerator, generator settings, and NetworkObjectTracker so network prefabs can be discovered, assigned stable FishNet prefab IDs, and registered when loaded through Addressables.
• Added the NetworkBarrier prefab, wired it into the boot scene through AssetSubSystem, and configured the generated NetworkObjects asset path.

Content Migration

• Generated 138 icon textures and metadata under Assets/Art/Generated/Icons.
• Migrated 138 tile/resource data assets to GUID-based prefab/icon references.
• Updated 198 world object prefabs plus relevant FishNet demo/system prefabs with asset identifiers, instance lifetime trackers, and network object trackers.
• Added/updated AssetDatabaseSettings, AddressablesCatalog, NetworkObjects.asset, PreloadCondition.asset, and NetworkObjectsGeneratorSettings.asset.
• Updated GenericObjectSo editor/preprocessor support and stopped generating runtime preview icons in TileResourceLoader; resources now use stored icons with a missing-icon fallback.

Gameplay Migration

• Migrated item spawning, inventory/container interactions, role loadouts, crafting, tile map placement/loading, construction holograms, audio playback, combat hit effects, body-part effects, furniture/locker/vendor/nuke interactions, boombox/noisy collision audio, and console item spawning to use AssetRequest/AssetHandle and the async network spawning path.
• Converted direct InstanceFinder.ServerManager.Spawn(...) call sites that depend on database assets to NetworkSpawner.SpawnAsync(...).
• Updated interaction icons and world-space UI loading to hold/release asset handles instead of repeatedly calling the old static database lookup.

Related Issues/PRs

Closes #1494