Steps 266-268: Phase 10a — semantic annotation core + sidecar persistence (32/32 tests)

Step 266: 5 semantic annotation AST types (Intent, Complexity, Risk,
Contract, SemanticTag) with JSON roundtrip and compact AST integration.
Step 267: Sidecar AST persistence (.whetstone/<file>.ast.json) with
save/load/list RPC methods, MCP tools, and permission enforcement.
Step 268: Phase 10a integration tests — multi-file sidecar workflow,
all 5 types in compact view, idempotent roundtrip, source isolation.

Also includes Sprint 10 plan, GUI/installer polish, and Emacs integration fixes.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

installer/linux/install.sh

@@ -42,7 +42,11 @@ if command -v apt-get &>/dev/null; then
     sudo apt-get install -y -qq \
         build-essential cmake git \
         libsdl2-dev libgl1-mesa-dev \
-        nlohmann-json3-dev
+        libglx-dev libopengl-dev \
+        nlohmann-json3-dev \
+        curl zip unzip tar \
+        autoconf autoconf-archive automake libtool \
+        python3-venv python3.12-venv
 elif command -v dnf &>/dev/null; then
     sudo dnf install -y \
         gcc-c++ cmake git \
@@ -69,7 +73,7 @@ if $DO_BUILD; then
 
     # Use the build script if available
     if [[ -x "$SCRIPT_DIR/build.sh" ]]; then
-        "$SCRIPT_DIR/build.sh" --config Release --system-packages
+        "$SCRIPT_DIR/build.sh" --config Release
     else
         mkdir -p "$BUILD_DIR"
         cmake -S "$EDITOR_DIR" -B "$BUILD_DIR" -DCMAKE_BUILD_TYPE=Release