Outline render order, stencil protection, JFA sentinel fix, diagnostics

Render order: 3-way M2 batch partition — game objects + local player
render first (write depth), then outline targets (stencil marks), then
other players/gear/NPCs. Outlines show through other players but are
occluded by world/WMO/game objects/local player.

Stencil protection: set STENCILWRITEMASK=0 after outline target DIPs
to prevent subsequent renders from overwriting stencil marks.

JFA sentinel: changed from (1,1) to (-1,-1) to move it outside UV
space. Did not fix banding but is correct regardless.

Debug: added DEBUG_SHOW_SILHOUETTE comptime flag to bypass JFA and
composite raw silhouette RT. Confirmed silhouette is clean — banding
is in the JFA pipeline, not stale vertex buffers.

Game object + local player tracking in tracker.zig for batch ordering.

Added project README and outline subsystem README documenting render
pipeline, architecture, known issues, and planned features.

src/outline/tracker.zig

@@ -45,6 +45,21 @@ pub var tracked_obj_count: usize = 0;
 var frame_outlines: [MAX_OUTLINE_MODELS]types.OutlineEntry = undefined;
 var frame_outline_count: usize = 0;
 
+// =============================================================================
+// Per-frame game object tracking (for render ordering — game objects first)
+// =============================================================================
+// Game object M2 models need to render before outline targets so their depth
+// is in the buffer when stencil marks are written. Tracked separately from
+// outline entries since game objects don't get outlines.
+
+const MAX_GAME_OBJ_MODELS = 256;
+
+var game_obj_ptrs: [MAX_TRACKED_OBJS]u32 = undefined;
+var game_obj_ptr_count: usize = 0;
+
+var game_obj_models: [MAX_GAME_OBJ_MODELS]u32 = undefined;
+var game_obj_model_count: usize = 0;
+
 // =============================================================================
 // Global enable flag
 // =============================================================================
@@ -88,6 +103,14 @@ pub fn getModelCategory(model_ptr: u32) types.ModelCategory {
     return entry.category;
 }
 
+/// Check if a model belongs to a game object (for render ordering).
+pub fn isGameObjectModel(model_ptr: u32) bool {
+    for (game_obj_models[0..game_obj_model_count]) |m| {
+        if (m == model_ptr) return true;
+    }
+    return false;
+}
+
 /// Get screen-space outline thickness in pixels for a category.
 pub fn getOutlinePixels(cat: types.ModelCategory) f32 {
     return switch (cat) {
@@ -124,6 +147,24 @@ pub fn classifyModel(model_ptr: u32) void {
             }
         }
     }
+
+    // Match against game object pointers (for render ordering).
+    if (game_obj_ptr_count > 0 and game_obj_model_count < MAX_GAME_OBJ_MODELS) {
+        for (game_obj_ptrs[0..game_obj_ptr_count]) |go_ptr| {
+            if (owner_callback == go_ptr or owner_direct == go_ptr) {
+                // Deduplicate
+                var found = false;
+                for (game_obj_models[0..game_obj_model_count]) |m| {
+                    if (m == model_ptr) { found = true; break; }
+                }
+                if (!found) {
+                    game_obj_models[game_obj_model_count] = model_ptr;
+                    game_obj_model_count += 1;
+                }
+                break;
+            }
+        }
+    }
 }
 
 fn addOutlineEntry(model_ptr: u32, cat: types.ModelCategory, mark: u8) void {
@@ -155,12 +196,21 @@ pub fn scanObjects() void {
     // Clear per-frame sets
     frame_outline_count = 0;
     tracked_obj_count = 0;
+    game_obj_ptr_count = 0;
+    game_obj_model_count = 0;
     resetDiag();
 
     if (!wow.isInGame()) return;
     const local_player = wow.getLocalPlayer();
     if (local_player == 0) return;
 
+    // Local player renders before outline targets (occludes outlines) unless
+    // the local player IS an outline target (partition logic checks outline first).
+    if (game_obj_ptr_count < MAX_TRACKED_OBJS) {
+        game_obj_ptrs[game_obj_ptr_count] = local_player;
+        game_obj_ptr_count += 1;
+    }
+
     // Cache raid target GUIDs
     wow.cacheRaidTargets();
 
@@ -197,6 +247,12 @@ pub fn scanObjects() void {
                     addTrackedObj(obj, .dead_player, 0);
                 }
             },
+            .game_object => {
+                if (game_obj_ptr_count < MAX_TRACKED_OBJS) {
+                    game_obj_ptrs[game_obj_ptr_count] = obj;
+                    game_obj_ptr_count += 1;
+                }
+            },
             else => {},
         }
     }