Implement bounded repository navigation with repo-lens

- Add map, find, and around commands with repository root discovery
- Stream literal ripgrep searches with match counts and result limits
- Add direct subprocess execution and explicit error returns
- Disable C++ exceptions and add navigation tests
- Support CMake installation and document builds and deployment
- Add a reusable agent skill and document skill discovery

include/process.hpp

@@ -0,0 +1,19 @@
+#pragma once
+
+#include <filesystem>
+#include <functional>
+#include <string>
+#include <string_view>
+#include <vector>
+
+namespace rl
+{
+struct process_result
+{
+	int exit_code;
+	std::string error;
+};
+// Streams stdout; stderr is retained up to 4096 bytes for diagnostics.
+[[nodiscard]] auto run_process(const std::vector<std::string>& args, const std::filesystem::path& directory,
+	const std::function<void(std::string_view)>& consume) noexcept -> process_result;
+} // namespace rl