feat: add Character Map (charmap) MTK app

A standalone Window Server app for browsing curated sets of characters
and copying them to the clipboard for pasting into other apps.

- Four sets (Latin, Punctuation, Currency, Symbols) shown as a responsive,
  scrollable tile grid with category tabs, a live preview/detail footer,
  and a Copy button.
- Click a tile (or use arrow keys + Enter/Space) to select and copy; a
  transient toast confirms the copy. Mouse wheel scrolls; Tab cycles sets.
- Styled with the MTK theme (accent, surfaces, rounded tiles) to match the
  other Montauk apps, modeled on the calculator app.

The character set is deliberately the single-byte Windows-1252 range the
system font can render (the glyph cache only holds codepoints 0-255).
Copying writes the raw byte, so glyphs render identically here and in every
other single-byte-text Montauk app (copying UTF-8 would render as mojibake).

Registered in programs/GNUmakefile and scripts/install_apps.sh alongside
calculator; menu category "Applications", icon accessories-character-map.svg.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

programs/src/charmap/Makefile

@@ -0,0 +1,86 @@
+# Makefile for charmap (standalone Character Map) on MontaukOS
+# Copyright (c) 2026 Daniel Hammer
+
+MAKEFLAGS += -rR
+.SUFFIXES:
+
+# ---- Toolchain ----
+
+TOOLCHAIN_PREFIX := $(shell cd ../../.. && pwd)/toolchain/local/bin/x86_64-elf-
+ifneq ($(wildcard $(TOOLCHAIN_PREFIX)gcc),)
+    CXX := $(TOOLCHAIN_PREFIX)g++
+else
+    CXX := g++
+endif
+
+# ---- Paths ----
+
+PROG_INC := ../../include
+LINK_LD  := ../../link.ld
+BINDIR   := ../../bin
+OBJDIR   := obj
+LIBDIR   := ../../lib
+
+# ---- Compiler flags ----
+
+CXXFLAGS := \
+    -std=gnu++20 \
+    -g -O2 -pipe \
+    -Wall \
+    -Wextra \
+    -Wno-unused-parameter \
+    -Wno-unused-function \
+    -nostdinc \
+    -ffreestanding \
+    -fno-stack-protector \
+    -fno-stack-check \
+    -fno-PIC \
+    -fno-rtti \
+    -fno-exceptions \
+    -ffunction-sections \
+    -fdata-sections \
+    -m64 \
+    -march=x86-64 \
+    -msse \
+    -msse2 \
+    -mno-red-zone \
+    -mcmodel=small \
+    -I $(PROG_INC) \
+    -isystem $(PROG_INC)/libc \
+    -isystem ../../../kernel/freestnd-c-hdrs/x86_64/include \
+    -isystem ../../../kernel/freestnd-cxx-hdrs/x86_64/include
+
+# ---- Linker flags ----
+
+LDFLAGS := \
+    -nostdlib \
+    -static \
+    -Wl,--build-id=none \
+    -Wl,--gc-sections \
+    -Wl,-m,elf_x86_64 \
+    -z max-page-size=0x1000 \
+    -T $(LINK_LD)
+
+# ---- Source files ----
+
+SRCS := main.cpp stb_truetype_impl.cpp font_data.cpp
+OBJS := $(addprefix $(OBJDIR)/,$(SRCS:.cpp=.o))
+
+# ---- Target ----
+
+TARGET := $(BINDIR)/apps/charmap/charmap.elf
+
+.PHONY: all clean
+
+all: $(TARGET)
+
+$(TARGET): $(OBJS) $(LINK_LD) Makefile
+	mkdir -p $(BINDIR)/apps/charmap
+	$(CXX) $(CXXFLAGS) $(LDFLAGS) $(OBJS) $(LIBDIR)/libc/liblibc.a -o $@
+
+$(OBJDIR)/%.o: %.cpp Makefile
+	mkdir -p $(OBJDIR)
+	$(CXX) $(CXXFLAGS) -c $< -o $@
+
+clean:
+	rm -rf $(OBJDIR) $(TARGET)