Add coverage build script for toasty_test

https://claude.ai/code/session_014MJB6stDN1p1kdUZkyhMca

build_feature.sh

@@ -0,0 +1,36 @@
+#!/bin/bash
+set -e
+
+TEST_BINARY="toasty_test_coverage"
+COVERAGE_DIR="coverage_html"
+
+echo "=== Step 1: Building test with coverage instrumentation ==="
+gcc src/sha256.c src/basic.c src/file_system.c src/byte_queue.c src/file_tree.c \
+    src/message.c src/tcp.c src/wal.c src/hash_set.c src/client.c \
+    src/metadata_server.c src/chunk_server.c src/random_client.c src/test_client.c src/main.c \
+    quakey/src/mockfs.c quakey/src/quakey.c \
+    -o "$TEST_BINARY" \
+    -Iquakey/include -Iinclude \
+    -Wall -Wextra -ggdb -O0 \
+    -DMAIN_TEST \
+    --coverage -fprofile-arcs -ftest-coverage
+echo "Build complete: $TEST_BINARY"
+
+echo ""
+echo "=== Step 2: Running tests ==="
+lcov --zerocounters --directory . --quiet
+lcov --capture --initial --directory . --output-file coverage_base.info --rc lcov_branch_coverage=1 --quiet
+"./$TEST_BINARY"
+echo "Tests finished"
+
+echo ""
+echo "=== Step 3: Generating coverage report ==="
+lcov --capture --directory . --output-file coverage_test.info --rc lcov_branch_coverage=1 --quiet
+lcov --add-tracefile coverage_base.info --add-tracefile coverage_test.info --output-file coverage.info --rc lcov_branch_coverage=1 --quiet
+lcov --remove coverage.info '/usr/*' 'quakey/*' --output-file coverage.info --rc lcov_branch_coverage=1 --quiet
+genhtml coverage.info --output-directory "$COVERAGE_DIR" --branch-coverage --quiet
+rm -f coverage_base.info coverage_test.info
+
+echo ""
+echo "=== Done ==="
+echo "Coverage report: $COVERAGE_DIR/index.html"