Implement AT-SPI selection bridging groundwork

Add the document selection adapter, integrate it through script utilities and major callers, and package the clipboard fallback work that was needed during manual testing on Wayland.

Also include a handoff note for the still-open browser link-selection issue so other developers can continue from the current branch state without reconstructing the debug trail.

build-local.sh

@@ -32,6 +32,25 @@ if ! python3 -c "import tomlkit" 2>/dev/null; then
     exit 1
 fi
 
+getPythonSiteDir() {
+    python3 -c 'import sys; print(f"{sys.version_info.major}.{sys.version_info.minor}")'
+}
+
+removeExistingLocalInstall() {
+    local pythonSite packageDir binPath desktopFile manPage
+    pythonSite="$HOME/.local/lib/python$(getPythonSiteDir)/site-packages"
+    packageDir="$pythonSite/cthulhu"
+    binPath="$HOME/.local/bin/cthulhu"
+    desktopFile="$HOME/.local/share/applications/cthulhu.desktop"
+    manPage="$HOME/.local/share/man/man1/cthulhu.1"
+
+    echo "Removing existing local installation targets..."
+    rm -f "$binPath"
+    rm -rf "$packageDir"
+    rm -f "$desktopFile"
+    rm -f "$manPage"
+}
+
 # Check for optional dependencies
 missingOptional=()
 if ! python3 -c "import gi" 2>/dev/null; then
@@ -63,6 +82,7 @@ meson compile -C _build
 
 # Install
 echo "Installing Cthulhu to ~/.local..."
+removeExistingLocalInstall
 meson install -C _build
 
 # Update desktop database and icon cache