gitignore: cover runtime data, boot headers, cross-compile outputs

ober

3eff3b0b0b731524cdd7f16120129248fb2b62ba

diff --git a/.gitignore b/.gitignore
index 77f2be4..8fe30cf 100644
--- a/.gitignore
+++ b/.gitignore
@@ -6,7 +6,7 @@
 jcode.json
 
 # Generated Scheme libraries (built from src/**/*.ss by jerbuild)
-/lib/**/*.sls
+/lib/
 /jcode_tui_shim.dylib
 /jcode_tui_shim.so
 
@@ -16,13 +16,19 @@ jcode.json
 /android/dist/
 /android/app/src/main/assets/native/
 
-# Cross-compile (make linux-amd64) artifacts
-/jcode-linux-amd64
-/jcode-linux-amd64-main.c
-/jcode-freebsd-amd64
-/jcode-freebsd-amd64-main.c
+# Runtime data (checkpoints, security cache, logs)
+/.jcode/
+/.jerboa/
+/jcode.log
+/.claude/
+
+# Cross-compile / boot-image build artifacts
 /petite_boot.h
 /scheme_boot.h
 /jcode_program.h
-.claude/
-.jcode/
+/jcode-freebsd-amd64
+/jcode-freebsd-amd64-main.c
+/jcode-linux-amd64
+/jcode-linux-amd64-main.c
+/jcode-linux-arm64
+/jcode-linux-arm64-main.c