chore: Move the bundle tool to .github/tools/bundle.sh

Update its repo-root path and all references (workflow, README, AGENTS.md).

.github/workflows/bundle.yml

@@ -1,4 +1,4 @@
-# Builds the single-file wizard (tools/bundle.sh) and publishes it as the
+# Builds the single-file wizard (.github/tools/bundle.sh) and publishes it as the
 # asset of the rolling "latest" release, for:
 #   curl -fsSL https://github.com/theupriser/cachyos-gamescope-boot/releases/download/latest/setup-gamescope-boot.sh | bash
 # Pull requests only build and check it.
@@ -22,7 +22,7 @@ jobs:
           fetch-depth: 0 # for the version in the bundle's header
 
       - name: Build
-        run: tools/bundle.sh dist/setup-gamescope-boot.sh
+        run: .github/tools/bundle.sh dist/setup-gamescope-boot.sh
 
       - name: Check
         run: |