fix(common): dynamic cf runtime path for local run

Author: nickchecan

bin/compile

@@ -139,18 +139,18 @@ if [ -f "pyproject.toml" ] && [ -f "uv.lock" ]; then
   # If the project uses a `src/` layout, include that too because the local
   # project itself is not installed by the exported third-party requirements.
   if [ -d "$SRC_DIR" ]; then
-    # Build droplet-relative paths at runtime because the app will launch from
-    # /home/vcap/app, not from the temporary staging directory used here.
+    # Resolve the app root from the sourced profile script so the same file
+    # works in both local smoke tests and the relocated CF droplet.
     cat > "$PROFILE_DIR/python.sh" <<EOF
-export APP_DIR="\${HOME}/app"
+export APP_DIR="\$(cd "\$(dirname "\${BASH_SOURCE[0]}")/.." && pwd)"
 export PATH="\$APP_DIR/.python/bin:\$APP_DIR/.python_packages/bin:\${PATH}"
 export PYTHONPATH="\$APP_DIR/src:\$APP_DIR/.python_packages/lib/python${PYTHON_VERSION}/site-packages:\${PYTHONPATH}"
 EOF
   else
     # Non-src-layout apps only need the staged site-packages directory plus the
     # buildpack-managed interpreter and console scripts on PATH.
     cat > "$PROFILE_DIR/python.sh" <<EOF
-export APP_DIR="\${HOME}/app"
+export APP_DIR="\$(cd "\$(dirname "\${BASH_SOURCE[0]}")/.." && pwd)"
 export PATH="\$APP_DIR/.python/bin:\$APP_DIR/.python_packages/bin:\${PATH}"
 export PYTHONPATH="\$APP_DIR/.python_packages/lib/python${PYTHON_VERSION}/site-packages:\${PYTHONPATH}"
 EOF

test/unit/compile_test.sh

@@ -216,7 +216,7 @@ test_compile_succeeds_for_locked_uv_project() {
   assert_path_exists "$export_file" "compile should write the exported requirements file"
   assert_path_exists "$shim_dir/python3" "compile should create a python3 shim for runtime commands"
   assert_path_exists "$shim_dir/python" "compile should create a python shim for runtime commands"
-  assert_file_contains "$profile_file" 'export APP_DIR="${HOME}/app"' "profile script should resolve paths from the droplet app directory at runtime"
+  assert_file_contains "$profile_file" 'export APP_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"' "profile script should resolve the app directory dynamically at runtime"
   assert_file_contains "$profile_file" '$APP_DIR/.python/bin:$APP_DIR/.python_packages/bin:${PATH}' "profile script should add the managed Python shims and staged console scripts to PATH"
   assert_file_contains "$profile_file" '$APP_DIR/.python_packages/lib/python3.13/site-packages:${PYTHONPATH}' "profile script should add staged dependencies to PYTHONPATH"
   assert_file_contains "$TEST_ROOT/uv.log" "python install 3.13" "compile should install the Python version pinned by .python-version"