Rename Step Line to Gig Line

Update the game name in project.godot, export presets, UI/marquee/title strings, packaging (AppImage/NSIS/desktop/appdata), tools, docs, and the generated prop GLBs. Packaging assets and README screenshots are regenerated. Headless suite 209/209 and Python tooling tests pass.

packaging/linux/AppRun

@@ -2,4 +2,4 @@
 # AppImage entry point: launch the bundled game binary.
 SELF="$(readlink -f "$0")"
 HERE="$(dirname "$SELF")"
-exec "${HERE}/usr/bin/step-line" "$@"
+exec "${HERE}/usr/bin/gig-line" "$@"

packaging/linux/build_appimage.sh

@@ -1,15 +1,15 @@
 #!/usr/bin/env bash
-# Build a self-contained Step Line AppImage (all game data included).
+# Build a self-contained Gig Line AppImage (all game data included).
 #
 # Prereqs: exported Linux binary in build/ (embed_pck=true), curl.
 # Usage:   bash packaging/linux/build_appimage.sh [version]
-# Output:  build/step-line-<version>-x86_64.AppImage
+# Output:  build/gig-line-<version>-x86_64.AppImage
 set -euo pipefail
 
 HERE="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
 ROOT="$(cd "$HERE/../.." && pwd)"
 VERSION="${1:-$(sed -n 's/.*config\/version="\([^"]*\)".*/\1/p' "$ROOT/project.godot")}"
-SRC_BIN="$ROOT/build/step-line-linux-${VERSION}.x86_64"
+SRC_BIN="$ROOT/build/gig-line-linux-${VERSION}.x86_64"
 
 if [[ ! -f "$SRC_BIN" ]]; then
   echo "error: missing $SRC_BIN — run ./tools/build_releases.sh first" >&2
@@ -18,20 +18,20 @@ fi
 
 WORK="$(mktemp -d)"
 trap 'rm -rf "$WORK"' EXIT
-APPDIR="$WORK/StepLine.AppDir"
+APPDIR="$WORK/GigLine.AppDir"
 mkdir -p "$APPDIR/usr/bin"
-cp "$SRC_BIN" "$APPDIR/usr/bin/step-line"
+cp "$SRC_BIN" "$APPDIR/usr/bin/gig-line"
 # The export embeds the PCK (embed_pck=true), so no extra data files are needed.
 
-cp "$HERE/step-line.desktop" "$APPDIR/step-line.desktop"
+cp "$HERE/gig-line.desktop" "$APPDIR/gig-line.desktop"
 cp "$HERE/AppRun" "$APPDIR/AppRun"
 chmod +x "$APPDIR/AppRun"
-cp "$HERE/step-line.png" "$APPDIR/step-line.png"
+cp "$HERE/gig-line.png" "$APPDIR/gig-line.png"
 # Desktop entry + metainfo in standard locations (AppStream validation requires
 # the metainfo filename to match the component id, and the .desktop discoverable).
 mkdir -p "$APPDIR/usr/share/applications" "$APPDIR/usr/share/metainfo"
-cp "$HERE/step-line.desktop" "$APPDIR/usr/share/applications/step-line.desktop"
-cp "$HERE/step-line.appdata.xml" "$APPDIR/usr/share/metainfo/net.stepline.game.appdata.xml"
+cp "$HERE/gig-line.desktop" "$APPDIR/usr/share/applications/gig-line.desktop"
+cp "$HERE/gig-line.appdata.xml" "$APPDIR/usr/share/metainfo/net.gigline.game.appdata.xml"
 
 TOOL="${APPIMAGE_TOOL:-/tmp/appimagetool-x86_64.AppImage}"
 if [[ ! -f "$TOOL" ]]; then
@@ -41,7 +41,7 @@ if [[ ! -f "$TOOL" ]]; then
   chmod +x "$TOOL"
 fi
 
-OUT="$ROOT/build/step-line-${VERSION}-x86_64.AppImage"
+OUT="$ROOT/build/gig-line-${VERSION}-x86_64.AppImage"
 echo "==> Building AppImage -> $OUT"
 # Extract-and-run avoids a FUSE dependency on the build host.
 APPIMAGE_EXTRACT_AND_RUN=1 "$TOOL" "$APPDIR" "$OUT"

packaging/linux/gig-line.appdata.xml

@@ -1,19 +1,19 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <component type="desktop-application">
-  <id>net.stepline.game</id>
-  <name>Step Line</name>
+  <id>net.gigline.game</id>
+  <name>Gig Line</name>
   <summary>Workplace security simulation on Hollywood Boulevard</summary>
   <url type="homepage">https://git.allucanget.biz/zwitschi/security-game</url>
-  <developer id="net.stepline"><name>Step Line Team</name></developer>
+  <developer id="net.gigline"><name>Gig Line Team</name></developer>
   <description>
     <p>
-      Step Line is a workplace security simulation about observation, communication,
+      Gig Line is a workplace security simulation about observation, communication,
       access verification, and proportionate escalation. Guard the steps and entrance
       of venues around Hollywood Boulevard: direct tourists, verify wristbands and IDs,
       screen guests, and escalate only when you have to.
     </p>
   </description>
-  <launchable type="desktop-id">step-line.desktop</launchable>
+  <launchable type="desktop-id">gig-line.desktop</launchable>
   <metadata_license>CC0-1.0</metadata_license>
   <project_license>MIT</project_license>
   <content_rating type="oars-1.1" />

packaging/linux/gig-line.desktop

@@ -1,9 +1,9 @@
 [Desktop Entry]
 Type=Application
-Name=Step Line
+Name=Gig Line
 Comment=Workplace security simulation on Hollywood Boulevard
-Exec=step-line
-Icon=step-line
+Exec=gig-line
+Icon=gig-line
 Terminal=false
 Categories=Game;Simulation;
 Keywords=security;simulation;hollywood;