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

docs/PROJECTMAP.md

@@ -2,28 +2,35 @@
 
 This is a routing table: **where should an agent look?** It is not an architecture manual. Start here, then inspect only the source or documentation relevant to the task.
 
-The repository contains a C++ CLI skeleton, native compiler presets, and a sample test. Navigation implementations remain TODOs. The bookmarks below route to existing build invariants, not implemented navigation features.
+The repository contains a functional C++ CLI with bounded `map`, `find`, and `around` commands, native compiler presets, and navigation tests. The bookmarks below route to existing build invariants, not implemented navigation features.
 
 ## Current routes
 
 ### Purpose and direction
 Path: `README.md`
-Entry: project purpose, scope, illustrative CLI, and measurement goals.
+Entry: project purpose, scope, implemented CLI, and measurement goals.
 Related: `AGENTS.md` for agent operating instructions.
 
-### CLI parsing and dispatch skeleton
+### CLI parsing and dispatch
 Path: `src/main.cpp`
 Entry: `main`
-Important symbols: `print_usage`, `extract_tool_name`, `extract_tool_arguments`
-Flow: placeholder parsing -> `find`/`map` dispatch -> tool `execute`; parsing and usage remain TODOs.
-Related: `src/CMakeLists.txt` lists all executable sources. `around` has a stub but is not dispatched yet.
+Important symbols: `print_usage`
+Flow: argv views -> `find`/`map`/`around` dispatch -> tool `execute`.
+Related: `src/CMakeLists.txt` lists all executable sources.
 
 ### Tool interface and implementations
 Path: `include/repo_tool_*.hpp`, `src/repo_tool_*.cpp`
 Entry: `include/repo_tool_interface.hpp`
 Important symbols: `rl::IRepoLensTool`, `rl::exit_code`, `rl::RepoLensToolFind`, `rl::RepoLensToolMap`, `rl::RepoLensToolAround`
-Related: `AGENTS.md` for trailing return types and the `[[nodiscard]]`/`noexcept` execution contract. Tool bodies remain TODOs.
-Tests: no navigation behavior tests yet.
+Related: `AGENTS.md` for trailing return types and the `[[nodiscard]]`/`noexcept` execution contract.
+Tests: `test/navigation_test.cpp` covers parsing, ranges, map ranking/limits, and subprocess/search behavior.
+
+### Repository navigation and subprocess support
+Path: `include/navigation.hpp`, `src/navigation.cpp`, `include/process.hpp`, `src/process.cpp`
+Entry: `rl::repository_root`, `rl::parse_location`, `rl::map_sections`, `rl::run_process`
+Flow: discover nearest `.git` ancestor -> query root-relative map/source or stream ripgrep output.
+Related: `src/repo_tool_find.cpp` limits occurrence locations; `src/repo_tool_around.cpp` reads the requested window; `src/repo_tool_map.cpp` queries map sections.
+Tests: `test/navigation_test.cpp` uses temporary repositories and a subprocess fixture in `test/test_main.cpp`.
 
 ### Native build and compiler settings
 Path: `CMakeLists.txt`, `CMakePresets.json`, `cmake/`, `src/CMakeLists.txt`
@@ -35,7 +42,7 @@ Ignore normally: generated `build/` and `.build/` trees; build helpers unless th
 
 ### Test dependencies and validation
 Path: `test/`, `cmake/gtest.cmake`
-Entry: `test/CMakeLists.txt`; `test/test_main.cpp` is only a sample assertion.
+Entry: `test/CMakeLists.txt`; `test/navigation_test.cpp` contains navigation tests; `test/test_main.cpp` supplies the test runner and subprocess fixture.
 Flow: `ENABLE_TESTS` -> FetchContent GoogleTest -> `repo-lens-test` -> CTest discovery.
 Bookmarks: `MSVC_SANITIZER_ANNOTATION_ALIGNMENT` in `test/CMakeLists.txt` keeps STL annotations consistent across the instrumented test and its dependencies.
 Related: `<compiler>-sanitizers` presets; `README.md` for local dependency overrides and build instructions.