Import art/VFX asset packs + game-feel systems; normalize texture extensions to lowercase for LFS

Add BefourStudios SciFi environment packs, Gabriel Aguiar VFX, and the
ShaderCrew Toon Shader embedded packages, plus combat/enemy/wave/death
gameplay systems and supporting vault docs/screenshots.

Rename 11 vendor textures from uppercase .PNG/.HDR to lowercase so the
case-sensitive Git LFS filters (*.png/*.hdr) match on case-sensitive
filesystems (Linux CI, case-sensitive macOS), not just locally where
core.ignorecase=true masks the gap. Each .meta moved with its asset so
GUID references are preserved. All ~1000 binaries tracked via LFS.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Docs/Vault/06_Roadmap/Backlog.md

@@ -21,7 +21,7 @@ Unordered pool of candidate work. Promote to a [[Milestones|milestone]] when com
 - [ ] **M2 follow-up — restart the editor to clear the corrupted Burst cache**, then confirm the console is clean on a warm play (no "not a known Burst entry point"). See [[2026-05-31_M2_Combat]] / [[DR-003_M2_Combat_Netcode_Architecture]].
 - [ ] **M2 follow-up — live interactive fire test** (focused Play Mode: press Space / LMB / RT → predicted projectile + dummy HP drop). The server combat loop + replication are validated; the input→`AbilityFireSystem`→predicted-spawn→classification path is only validated structurally.
 - [ ] **M2 follow-up — mouse-cursor aim for KBM** (needs a camera ground-ray rig); currently aim = gamepad right-stick + movement-heading fallback.
-- [ ] **M2 follow-up — player death/respawn** (M2 only clamps player HP ≥ 0; dummies despawn on death).
+- [x] **M2 follow-up — player death/respawn** — done in **M5.5**: derived `Dead` enableable gate (from replicated Health) + server `PlayerRespawnSystem` (full HP + reposition to base after a delay). [[DR-009_GameFeel_Identity_FirstBlood]]
 - [ ] M2 polish — projectile/dummy visuals (primitive meshes/materials currently); optional predicted client-side auto-target if the soft server reconcile feels off.
 - [ ] **M3 follow-up — UI/icon/description pipeline** for abilities (managed lookup keyed by `AbilityId`, off the blob). Deferred from M3 ([[2026-05-31_M3_Data_Driven_Abilities]]).
 - [ ] **M3 follow-up — timed / removable modifiers** (expiry on `NetworkTick`, `ClearByType` via `StatModifier.SourceId`). M3 modifiers are permanent-once-granted.
@@ -42,4 +42,16 @@ Unordered pool of candidate work. Promote to a [[Milestones|milestone]] when com
 - [ ] **M5b follow-up — CC package version**: 1.4.2 declares `entities/physics@1.3.x` (resolves via SemVer floor on our 6.4.0/1.4.6). Move to a CC build explicitly targeting Entities 6.x when published.
 - [ ] **M5 follow-up — physics lag compensation** (`NetCodePhysicsConfig.EnableLagCompensation` + `PhysicsWorldHistorySingleton`) if/when physics-based hit detection replaces the swept-segment server check.
 - [ ] **M5 follow-up — projectiles as physics bodies** (currently kinematic + swept hit); convert for projectile-vs-world collision.
-- [ ] **M5 follow-up — hard rotation lock** (`PhysicsMass.InverseInertia=0`); `Rigidbody.FreezeRotation` is not honored by the DOTS baker, so rotation is held by per-tick angular-zero + aim write.
+- [ ] **M5 follow-up — hard rotation lock** (`PhysicsMass.InverseInertia=0`); `Rigidbody.FreezeRotation` is not honored by the DOTS baker, so rotation is held by per-tick angular-zero + aim write.
+- [x] **Game identity defined** — sci-fi **frontier colony** fiction ([[Identity]]), layered over [[Pillars]] with no mechanical rework. Resolves the "mechanics without a fiction" gap. Delivered with M5.5 ([[DR-009_GameFeel_Identity_FirstBlood]]).
+- [x] **M2 polish — projectile/dummy visuals** — addressed by the M5.5 emissive palette + URP post-processing (cyan crew, cyan projectiles, orange Husks, dark walls/ground). Real models/animation still deferred.
+- [x] **M5.5 follow-up — auto-target on Husks** — done (deepening pass): `AbilityFireSystem` candidate query `.WithAny<TrainingDummyTag, EnemyTag>()`. [[2026-06-02_GameFeel_Deepening]]
+- [x] **M5.5 follow-up — respawn safety** — done (deepening pass): replicated `RespawnInvuln` window (server-enforced damage immunity + HUD SHIELDED cue). [[2026-06-02_GameFeel_Deepening]]
+- [x] **M5.5 follow-up — enemy variety + wave/threat director** — done (deepening pass): `WaveSystem` escalating waves (lull → spawn → clear → bigger) + 3 melee Husk variants (Grunt/Swarmer/Brute) round-robin from a baked pool. Ranged spitter + broodmaker/boss still open. [[2026-06-02_GameFeel_Deepening]]
+- [ ] **Deepening follow-up — ranged Husk (Spitter)**: a server-spawned enemy-projectile subsystem for dodge depth (the next variety type; melee-only today).
+- [ ] **Deepening follow-up — wave number on HUD**: needs a replicated game-state ghost (`WaveState` is server-only); the live "HUSKS N" count conveys threat for now.
+- [ ] **Deepening follow-up — boss / per-wave composition weighting** (brutes later, swarms early) instead of flat round-robin; a "broodmaker" that spawns.
+- [ ] **Deepening follow-up — server perf under wave load**: investigate the in-editor tick-batching (Burst cache health, multi-world cost); validate in a real build.
+- [ ] **M5.5 follow-up — real assets**: authored audio (replace procedural SFX), stylized hard-surface crew/structures + corrupted-biomech Husks (replace primitives), TextMeshPro HUD; add the URP **SSAO** renderer feature for more depth.
+- [ ] **M5.5 follow-up — multi-client juice/HUD**: validate remote-player death VFX (interpolation-timeline `Health==0`) + per-client HUD under two clients (pairs with the deferred M4/M5b two-build tests).
+- [ ] **M5.5 follow-up — difficulty balance**: Husks tuned for a real moving/shooting player (dmg 5, strike 48 ticks, speed 3, `MaxAlive` 6); revisit once movement/fire feel is tuned and enemy variety lands.