chore(assets): delete four unreferenced brand exports

The four llamacasty-* files were source exports, not assets: shipped art is
embedded via <Resource> in ytLive.csproj and read through pack: URIs, and the
Store tiles derive from Assets/llamacasty-logo.jpg. None of the four appears in
the csproj, any XAML Source/Icon, or a script, so they were dead weight that
kept resurfacing as untracked noise.

MyMistakes.md gains the recipe (csproj list + grep = 30-second verdict) so a
loose file in Assets/ is never re-litigated; HANDOFF drops the stale note.

HANDOFF.md

@@ -8,7 +8,8 @@
   preview and output. The frame pump only reads the raster cache; no WPF render occurs on its thread.
 - The app clean build has 0 warnings. 524 tests passed with the documented physical mouse-injection test
   and known audio test excluded; the new text renderer, preview/output, and pump-cache tests pass.
-- The four untracked `Assets/llamacasty-*` files remain untouched.
+- The four stray `Assets/llamacasty-*` exports were deleted 2026-11-04 — unreferenced by the csproj,
+  XAML or scripts (recipe in `MyMistakes.md`).
 
 ## Next action
 

MyMistakes.md

@@ -35,6 +35,30 @@ max 200.
 
 ## 🔬 Recipes registry
 
+### A LOOSE FILE IN `Assets/` IS NOT AN ASSET — THE CSProj LIST IS (RECIPE, 2026-11-04)
+
+**Problem:** four untracked `Assets/llamacasty-*` exports sat in the tree for days, reported in
+`HANDOFF.md` as "untouched", and every session spent tokens re-litigating whether to commit them.
+
+**What it actually is:** shipped art is embedded in the assembly via **`<Resource Include="Assets\…"/>`**
+in `ytLive.csproj` (icons, logo, backgrounds, fonts) or `<EmbeddedResource>` (the ONNX model), and the
+Store tiles in `Packaging/Assets/` are generated from `Assets/llamacasty-logo.jpg` by
+`scripts/make-store-logos.py`. The app reads art through `pack://`/`/LlamaCasty;component/Assets/…`
+URIs — it never loads a file from disk at runtime. So a loose `.jpg`/`.png` in `Assets/` that appears in
+**neither** the csproj nor any `Source=`/`Icon=`/script is a **source export**, not a dependency.
+
+**The recipe (30 seconds, do it before mentioning the file):**
+1. `git status --short` → the untracked list.
+2. For each file: `grep -rIn -F "<name>" --exclude-dir=.git --exclude-dir=bin --exclude-dir=obj .`
+   plus `grep -n 'Assets' ytLive.csproj`. **No hit in either = dead.** (Check `scripts/` too — a
+   generator can be the only consumer.)
+3. Referenced → add it to `<Resource>` **and** commit it in the same unit. Unreferenced → `rm` it and
+   commit the deletion; do not park it in `HANDOFF.md`.
+
+**Deleted 2026-11-04 by this rule:** `llamacasty-icon.jpg`, `llamacasty-logo-white.jpg`,
+`llamacasty-logo-white-nobg.png`, `llamacasty-logo-white-nobg-dim.png` — the shipped brand art is
+`llamacasty-icon.ico`/`.png` and `llamacasty-logo.jpg`, all three already tracked and embedded.
+
 ### DEPLOYING llamacasty.com TO THE DROPLET (RECIPE, 2026-10-30)
 
 **Problem:** "upload the site" burned a session: `ssh -p 2214 gramps@llamachile.tube` hung on a