Add stamp source hashing and maximize test infrastructure

- Add source hashing to stamp system (functions.sh) for detecting
  when dependencies need rebuild based on source file changes
- Update build-pcbnew.sh to use source stamps for wxWidgets
- Add global-setup.ts to clean logs before test runs
- Add maximize_test standalone test to verify wxFrame::Maximize()
  works correctly in WASM (it does - window is 1280x720)
- Update Makefile.wasm with maximize test build rules

The maximize_test proves wxWidgets display detection works fine.
KiCad's 20x20 window bug is KiCad-specific, not a wxWidgets issue.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

scripts/common/functions.sh

@@ -193,6 +193,81 @@ remove_stamp() {
     rm -f "$stamp_file"
 }
 
+# Compute hash of source files in a directory
+# Usage: compute_source_hash /path/to/source "*.cpp" "*.h"
+compute_source_hash() {
+    local source_dir="$1"
+    shift
+    local patterns=("$@")
+
+    # Build find command for all patterns
+    local find_args=()
+    for pattern in "${patterns[@]}"; do
+        if [ ${#find_args[@]} -gt 0 ]; then
+            find_args+=("-o")
+        fi
+        find_args+=("-name" "$pattern")
+    done
+
+    # Hash all matching files (sorted for consistency)
+    # Use md5 on macOS, md5sum on Linux (Docker)
+    if command -v md5 &>/dev/null; then
+        find "$source_dir" -type f \( "${find_args[@]}" \) 2>/dev/null | \
+            sort | \
+            xargs cat 2>/dev/null | \
+            md5
+    else
+        find "$source_dir" -type f \( "${find_args[@]}" \) 2>/dev/null | \
+            sort | \
+            xargs cat 2>/dev/null | \
+            md5sum | \
+            cut -d' ' -f1
+    fi
+}
+
+# Create stamp with source hash
+# Usage: create_source_stamp "wxwidgets" /path/to/source "*.cpp" "*.h"
+create_source_stamp() {
+    local name="$1"
+    local source_dir="$2"
+    shift 2
+    local patterns=("$@")
+
+    local stamp_dir="${BUILD_ROOT:-$PROJECT_ROOT/build-wasm}/stamps"
+    mkdir -p "$stamp_dir"
+    local stamp_file="$stamp_dir/$name.stamp"
+
+    local hash=$(compute_source_hash "$source_dir" "${patterns[@]}")
+    echo "$hash" > "$stamp_file"
+    log_info "Created stamp: $name (hash: ${hash:0:8}...)"
+}
+
+# Check if source stamp is still valid
+# Usage: check_source_stamp "wxwidgets" /path/to/source "*.cpp" "*.h"
+# Returns: 0 if valid (no rebuild needed), 1 if invalid (rebuild needed)
+check_source_stamp() {
+    local name="$1"
+    local source_dir="$2"
+    shift 2
+    local patterns=("$@")
+
+    local stamp_file="${BUILD_ROOT:-$PROJECT_ROOT/build-wasm}/stamps/$name.stamp"
+
+    if [ ! -f "$stamp_file" ]; then
+        return 1  # No stamp, need build
+    fi
+
+    local stored_hash=$(cat "$stamp_file")
+    local current_hash=$(compute_source_hash "$source_dir" "${patterns[@]}")
+
+    if [ "$stored_hash" = "$current_hash" ]; then
+        return 0  # Up to date
+    else
+        log_info "Source changed for $name (${stored_hash:0:8}... -> ${current_hash:0:8}...)"
+        return 1  # Changed, need rebuild
+    fi
+}
+
 # Build if stamp doesn't exist
 build_if_needed() {
     local name="$1"

scripts/kicad/build-pcbnew.sh

@@ -12,6 +12,11 @@
 #   --debug       Build with debug symbols (default)
 #   --release     Build optimized without debug symbols
 #   -j N          Parallel compilation jobs (default: 1)
+#
+# Stamp System:
+#   Dependencies use source-hash stamps to detect when rebuilds are needed.
+#   wxWidgets rebuilds automatically when source files (*.cpp, *.h, *.c) change.
+#   To force a rebuild, delete the stamp: rm -f build-wasm/stamps/wxwidgets.stamp
 
 set -e
 
@@ -101,16 +106,13 @@ if [ $NO_CLEAN -eq 1 ] && check_stamp "${KICAD_STAMP}"; then
     exit 0
 fi
 
-# Step 4: Build wxWidgets if not present
-WXWIDGETS_STAMP="${BUILD_ROOT}/stamps/wxwidgets.stamp"
-if [ ! -f "${WX_BUILD}/lib/libwx_baseu-3.2.a" ]; then
+# Step 4: Build wxWidgets if source changed or not present
+WX_SOURCE="${PROJECT_ROOT}/wxwidgets/src"
+if [ ! -f "${WX_BUILD}/lib/libwx_baseu-3.2.a" ] || \
+   ! check_source_stamp "wxwidgets" "$WX_SOURCE" "*.cpp" "*.h" "*.c"; then
     log_info "Building wxWidgets..."
     "${SCRIPT_DIR}/../build-wxuniversal-wasm.sh" --no-clean
-    # Create stamp after successful build
-    touch "${WXWIDGETS_STAMP}"
-elif [ ! -f "${WXWIDGETS_STAMP}" ]; then
-    # Library exists but no stamp - create one
-    touch "${WXWIDGETS_STAMP}"
+    create_source_stamp "wxwidgets" "$WX_SOURCE" "*.cpp" "*.h" "*.c"
 fi
 
 log_info "Building KiCad PCBnew ${KICAD_VERSION} for WASM..."