refactor(build): fold calculator into unified docker/build.sh dispatch

Convert the calculator port (commit 0464470) from the parallel/copy-paste
pattern to the dispatch pattern used by pcbnew + eeschema.

- docker/build.sh: <app> is now required (no pcbnew default); missing,
  unknown, and --help paths all print "pcbnew | eeschema | calculator | all".
  Adds calculator to build_app() via kicad_subdir_for() (pcb_calculator
  inner subdir, calculator.* output basename). Also fixes the
  EMSDK=/emsdkkicad-wasm-builder typo that snuck in during the calc merge.
- scripts/kicad/build-kicad-target.sh: accepts calculator; introduces
  KICAD_TARGET (pcb_calculator for calc, == APP_NAME otherwise) used for
  the make target, embind include path, and final-log line.
- scripts/kicad/build-calculator.sh: 305-line copy of build-pcbnew.sh
  collapsed to a 7-line wrapper around build-kicad-target.sh.
- tests/scripts/setup-kicad-wasm.sh: copy_app calculator added with the
  same pcb_calculator subdir mapping for the docker-volume fallback path.
- tests/package.json: test:calculator* routed through the shared
  playwright-kicad.config.ts kicad/calculator.spec.ts (mirrors eeschema).
- Delete: docker/build-calculator.sh, tests/scripts/setup-calculator-wasm.sh,
  tests/playwright-calculator.config.ts.

Bumps wxwidgets d1d1627 -> 6fb2eac (origin/wasm-port). The new sha includes
"unic/combobox: add GetCurrentSelection() inline default" which calc's
kicad/pcb_calculator/widgets/unit_selector.cpp needs to compile. Without
this bump the unified dispatch would expose calc as a buildable target but
the build itself would fail. Verified: build.sh all completes clean across
all three apps; pcbnew/eeschema e2e pass; calc compiles and launches (test
stability separate from this refactor).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

scripts/kicad/build-kicad-target.sh

@@ -1,11 +1,11 @@
 #!/bin/bash
-# Build a KiCad editor (pcbnew or eeschema) for WebAssembly.
+# Build a KiCad app (pcbnew, eeschema, calculator) for WebAssembly.
 #
 # Usage:
 #   ./scripts/kicad/build-kicad-target.sh <app> [options]
 #
 # Args:
-#   <app>         pcbnew | eeschema (required)
+#   <app>         pcbnew | eeschema | calculator (required)
 #
 # Options:
 #   --full        Full clean rebuild (dependencies + KiCad)
@@ -16,25 +16,35 @@
 #   --diag=...    Diagnostic preprocessor flags (gal, coroutine, ctor, all)
 #   -j N          Parallel compilation jobs (default: 1)
 #
-# Each editor builds into its own tree: build-wasm/kicad-<app>/.
-# Per-editor extras live alongside generic stubs:
+# Each app builds into its own tree: build-wasm/kicad-<app>/.
+# Per-app extras live alongside generic stubs:
 #   - wasm/bindings/<app>_embind.cpp        (optional)
 #   - wasm/stubs/<app>_frame_stub.cpp       (optional, app-specific stubs)
 #   - wasm/stubs/<app>_scripting_stub.cpp   (optional, app-specific scripting stubs)
+#
+# Most apps use the same name for the user-facing app, the CMake target, and
+# the source subdirectory. Calculator is the exception: app=calculator but the
+# upstream target and source subdir are both pcb_calculator (the OUTPUT_NAME
+# property in pcb_calculator/CMakeLists.txt emits calculator.{js,wasm}).
 
 set -e
 
 if [ -z "$1" ]; then
-    echo "Error: missing <app> argument (pcbnew | eeschema)" >&2
+    echo "Error: missing <app> argument (pcbnew | eeschema | calculator)" >&2
     exit 1
 fi
 APP_NAME="$1"
 shift
 
 case "$APP_NAME" in
-    pcbnew|eeschema) ;;
+    pcbnew|eeschema)
+        KICAD_TARGET="$APP_NAME"
+        ;;
+    calculator)
+        KICAD_TARGET="pcb_calculator"
+        ;;
     *)
-        echo "Error: unknown app '$APP_NAME' (expected: pcbnew | eeschema)" >&2
+        echo "Error: unknown app '$APP_NAME' (expected: pcbnew | eeschema | calculator)" >&2
         exit 1
         ;;
 esac
@@ -362,7 +372,7 @@ emcmake cmake "${KICAD_DIR}" \
 if [ -f "${EMBIND_SRC}" ]; then
     log_info "Compiling Embind bindings (${APP_NAME})..."
     # Use the same includes and flags that KiCad uses
-    KICAD_INCLUDES="-I${KICAD_BUILD} -I${KICAD_DIR}/include -I${KICAD_DIR}/${APP_NAME} -I${KICAD_DIR}/common"
+    KICAD_INCLUDES="-I${KICAD_BUILD} -I${KICAD_DIR}/include -I${KICAD_DIR}/${KICAD_TARGET} -I${KICAD_DIR}/common"
     KICAD_INCLUDES+=" -I${KICAD_DIR}/libs/core/include -I${KICAD_DIR}/libs/kimath/include -I${KICAD_DIR}/libs/kiplatform/include"
     KICAD_INCLUDES+=" -I${KICAD_DIR}/thirdparty/clipper2/Clipper2Lib/include"
     KICAD_INCLUDES+=" -I${KICAD_DIR}/thirdparty/nlohmann_json"
@@ -381,8 +391,8 @@ else
 fi
 
 # Step 8: Build the app target
-log_info "Building ${APP_NAME}..."
-emmake make -j${JOBS} "${APP_NAME}"
+log_info "Building ${APP_NAME} (CMake target: ${KICAD_TARGET})..."
+emmake make -j${JOBS} "${KICAD_TARGET}"
 
 # Step 8.1: Build bitmap resources (images.tar.gz)
 # This creates the icon archive that KiCad loads at runtime
@@ -392,4 +402,4 @@ emmake make bitmap_archive_build
 # Step 9: Create stamp file
 create_stamp "${KICAD_STAMP}"
 log_info "KiCad ${APP_NAME} build complete!"
-log_info "Output: ${KICAD_BUILD}/${APP_NAME}/${APP_NAME}.js"
+log_info "Output: ${KICAD_BUILD}/${KICAD_TARGET}/${APP_NAME}.js"