chore: import upstream snapshot with attribution

scripts/vendor-grammar.sh

@@ -0,0 +1,90 @@
+#!/usr/bin/env bash
+# vendor-grammar.sh: Vendor a single tree-sitter grammar into internal/cbm/vendored/grammars/<name>/
+# Usage: ./scripts/vendor-grammar.sh <repo_url> <name> [subdir]
+#   repo_url: GitHub repository URL (e.g., https://github.com/tree-sitter/tree-sitter-json)
+#   name:     Target directory name (e.g., json)
+#   subdir:   Optional subdirectory within repo containing src/ (e.g., "fsharp" for monorepo grammars)
+
+set -euo pipefail
+
+REPO_URL="$1"
+NAME="$2"
+SUBDIR="${3:-}"
+
+SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
+PROJECT_DIR="$(dirname "$SCRIPT_DIR")"
+GRAMMAR_DIR="$PROJECT_DIR/internal/cbm/vendored/grammars/$NAME"
+TMPDIR="$(mktemp -d)"
+
+trap 'rm -rf "$TMPDIR"' EXIT
+
+echo "Vendoring $NAME from $REPO_URL..."
+
+git clone --depth 1 "$REPO_URL" "$TMPDIR/repo" 2>/dev/null
+
+SRC_DIR="$TMPDIR/repo/src"
+if [ -n "$SUBDIR" ]; then
+    SRC_DIR="$TMPDIR/repo/$SUBDIR/src"
+fi
+
+if [ ! -f "$SRC_DIR/parser.c" ]; then
+    echo "ERROR: $SRC_DIR/parser.c not found" >&2
+    exit 1
+fi
+
+mkdir -p "$GRAMMAR_DIR/tree_sitter"
+
+cp "$SRC_DIR/parser.c" "$GRAMMAR_DIR/"
+
+if [ -f "$SRC_DIR/scanner.c" ]; then
+    cp "$SRC_DIR/scanner.c" "$GRAMMAR_DIR/"
+fi
+if [ -f "$SRC_DIR/scanner.cc" ]; then
+    echo "WARNING: $NAME has C++ scanner (scanner.cc) — needs special handling" >&2
+fi
+
+# Copy tree_sitter headers
+if [ -d "$SRC_DIR/tree_sitter" ]; then
+    cp "$SRC_DIR/tree_sitter/"*.h "$GRAMMAR_DIR/tree_sitter/" 2>/dev/null || true
+fi
+
+# Copy any extra headers (.h, .inc files) used by scanners
+# Examples: tag.h (Vue/Svelte/Astro), unicode.h (PureScript/Typst),
+# TokenTree.h/.inc (VHDL)
+for f in "$SRC_DIR"/*.h "$SRC_DIR"/*.inc; do
+    [ -f "$f" ] && cp "$f" "$GRAMMAR_DIR/"
+done
+# Copy common/ subdirectory if present (e.g., F# scanner uses common/scanner.h)
+if [ -d "$SRC_DIR/common" ]; then
+    cp -r "$SRC_DIR/common" "$GRAMMAR_DIR/"
+fi
+
+# Copy LICENSE file from upstream repo
+REPO_ROOT="$TMPDIR/repo"
+if [ -n "$SUBDIR" ]; then
+    # For monorepos, check subdir first, then repo root
+    if [ -f "$REPO_ROOT/$SUBDIR/LICENSE" ]; then
+        cp "$REPO_ROOT/$SUBDIR/LICENSE" "$GRAMMAR_DIR/LICENSE"
+    elif [ -f "$REPO_ROOT/LICENSE" ]; then
+        cp "$REPO_ROOT/LICENSE" "$GRAMMAR_DIR/LICENSE"
+    elif [ -f "$REPO_ROOT/LICENSE.md" ]; then
+        cp "$REPO_ROOT/LICENSE.md" "$GRAMMAR_DIR/LICENSE"
+    elif [ -f "$REPO_ROOT/COPYING" ]; then
+        cp "$REPO_ROOT/COPYING" "$GRAMMAR_DIR/LICENSE"
+    else
+        echo "WARNING: No LICENSE file found for $NAME" >&2
+    fi
+else
+    if [ -f "$REPO_ROOT/LICENSE" ]; then
+        cp "$REPO_ROOT/LICENSE" "$GRAMMAR_DIR/LICENSE"
+    elif [ -f "$REPO_ROOT/LICENSE.md" ]; then
+        cp "$REPO_ROOT/LICENSE.md" "$GRAMMAR_DIR/LICENSE"
+    elif [ -f "$REPO_ROOT/COPYING" ]; then
+        cp "$REPO_ROOT/COPYING" "$GRAMMAR_DIR/LICENSE"
+    else
+        echo "WARNING: No LICENSE file found for $NAME" >&2
+    fi
+fi
+
+echo "Vendored $NAME to $GRAMMAR_DIR"
+ls -la "$GRAMMAR_DIR/"