diff --git a/HANDOFF.md b/HANDOFF.md
index 924fbc5..b86f2bf 100644
--- a/HANDOFF.md
+++ b/HANDOFF.md
@@ -30,10 +30,13 @@
   fixtures in `ytLive.Tests/Fixtures/`).
 
 ## Known issues / follow-ups
+- **64-bit only (2026-10-09):** `PlatformTarget=x64` in both csproj files (verified: ytLive.dll PE
+  machine 0x8664, 408/408 green). TASK 48 item 2 carries the x64-only MSIX + `-r win-x64` publish.
 - `onnxruntime.dll` is ~17 MB; an RID-less build copies every RID's native folder — TASK 48's MSIX
   publish must pin win-x64.
-- `THIRD-PARTY-NOTICES.txt` header still says "paid, closed-source product" (pre free-forever) — noted,
-  not changed (out of scope).
+- `THIRD-PARTY-NOTICES.txt` header + ai.md Licensing/packaging sections still say "paid,
+  closed-source" / Store IAP / branding-flash paid delta (pre free-forever + planned public GPL-3.0
+  release) — the creator is choosing the license; rewrite those with it.
 - Carried: "Use default background" toggle still not working (from 2026-10-07).
 
 ## Next step
diff --git a/TASKS/task-48-distribution-msix.md b/TASKS/task-48-distribution-msix.md
index ad2a1e2..c2d7977 100644
--- a/TASKS/task-48-distribution-msix.md
+++ b/TASKS/task-48-distribution-msix.md
@@ -151,6 +151,10 @@ There is currently **no `.manifest` file in the repo at all**, so this is purely
 - Declare **English only** (10.7 — otherwise the description must be localized into every
   declared language)
 - Block map SHA2-256, `StoreManifest`, under the 25 GB cap
+- **x64 only** (64-bit requirement, creator ruling 2026-10-09 — `PlatformTarget=x64` already in
+  both csproj files): package architecture `x64`, publish with `-r win-x64` so only the win-x64
+  native folders ship (an RID-less build copies every RID's ONNX Runtime native, ~17 MB each).
+  Store listing system requirements: "64-bit Windows 10 or 11".
 
 **Do NOT use `appContainer`** — see the invariant in item 6.
 
diff --git a/ai.md b/ai.md
index c4b0b5a..25f2e9b 100644
--- a/ai.md
+++ b/ai.md
@@ -2245,6 +2245,13 @@ before re-deriving it. Executable checklist: `TASKS/task-48-distribution-msix.md
   thinks I'm expired" bug class along with the offline-grace machine.
 - **⛔ Bundle ffmpeg — no runtime downloads** (Store policy 10.2.2; also the 2026-09-01 404).
   See the FFmpeg locator section above. **This is the first code unit.**
+- **⛔ 64-bit Windows only (creator ruling 2026-10-09).** Both csproj files set
+  `<PlatformTarget>x64</PlatformTarget>` (the test project too — an AnyCPU test project
+  referencing an x64 app raises MSB3270 and breaks the 0-warning gate). Why: the bundled ffmpeg
+  is the win64 build, ONNX Runtime 1.31 ships no win-x86 native (only win-x64/win-arm64), and a
+  32-bit address space can't hold the 1080p frame buffers. Windows 11 is 64-bit-only anyway. The
+  MSIX publish targets x64 only (ARM64 is a possible later add: both ffmpeg and ONNX Runtime have
+  arm64 builds). Public copy says "64-bit Windows 10 or 11".
 
 **What does NOT change: the monetization posture.** Free gets everything; the branding flash
 stays the **only** paid delta (`TASK 36` item 2). Store IAP changes how `IsPremium` is
diff --git a/ytLive.Tests/ytLive.Tests.csproj b/ytLive.Tests/ytLive.Tests.csproj
index 7dd1042..1ade8de 100644
--- a/ytLive.Tests/ytLive.Tests.csproj
+++ b/ytLive.Tests/ytLive.Tests.csproj
@@ -6,6 +6,9 @@
     <ImplicitUsings>enable</ImplicitUsings>
     <IsPackable>false</IsPackable>
     <EnableWindowsTargeting>true</EnableWindowsTargeting>
+    <!-- Matches the app (64-bit only) — an AnyCPU test project referencing an x64 app
+         raises MSB3270 (architecture mismatch) and breaks the 0-warning gate. -->
+    <PlatformTarget>x64</PlatformTarget>
   </PropertyGroup>
 
   <ItemGroup>
diff --git a/ytLive.csproj b/ytLive.csproj
index 043b185..08f687c 100644
--- a/ytLive.csproj
+++ b/ytLive.csproj
@@ -10,6 +10,11 @@
     <ApplicationIcon>Assets\llamacasty-icon.ico</ApplicationIcon>
     <AssemblyName>ytLive</AssemblyName>
     <RootNamespace>ytLive</RootNamespace>
+    <!-- 64-bit Windows only (creator ruling 2026-10-09). The bundled ffmpeg is the win64 build
+         and ONNX Runtime ships no win-x86 native, so a 32-bit process could never stream; a
+         32-bit address space (2–4 GB) would also choke on 1080p frame buffers. x64 makes the
+         exe refuse to start on 32-bit Windows instead of failing at Go Live. -->
+    <PlatformTarget>x64</PlatformTarget>
   </PropertyGroup>
 
   <ItemGroup>