update AGENT.md and README.md to match current state

AGENT.md

@@ -29,7 +29,6 @@
 ## Git Workflow
 - Small commits with logical separation
 - Concise commit messages
-- Claude footer: short one-liner only
 
 ## Session Summaries
 - When user requests session summary, create in docs/session_summaries/
@@ -39,7 +38,6 @@
 
 ## Common Commands
 - Build: make
-- Run: ./orbit_sim [config_file]
 - Test: make test
 - See README.md for full build instructions
 

README.md

@@ -6,7 +6,6 @@ A 3D orbital mechanics simulation using a 2-body gravitational model with sphere
 
 - 2-body gravitational physics with SOI transitions
 - Configurable star systems via toml files
-- Solar system example configurations
 
 ## Getting Started
 
@@ -23,7 +22,8 @@ git submodule update --init --recursive  # If already cloned without --recursive
 ```bash
 sudo apt update
 sudo apt install -y build-essential g++ make libx11-dev libxcursor-dev \
-    libxrandr-dev libxinerama-dev libxi-dev libgl1-mesa-dev libglu1-mesa-dev
+    libxrandr-dev libxinerama-dev libxi-dev libgl1-mesa-dev libglu1-mesa-dev \
+    libcatch2-dev
 ```
 
 ### Building
@@ -49,13 +49,6 @@ make clean-all    # Clean everything including raylib
 ```bash
 make test              # Run full automated test suite
 ```
-
-The test suite validates:
-- Orbital period accuracy (Earth, Mars)
-- Energy conservation (RK4 integration)
-- SOI transitions and multi-body interactions
-- Eccentric orbit behavior (comets, parabolic, hyperbolic)
-
 All tests use Catch2 framework with configurable time steps and durations.
 
 ## License