Initial commit: design spec for session retrospective tool

Claude Code session efficiency analysis tool — self-assessment of
action impact + token/time retrospectives via JSONL parsing.

.gitignore

@@ -0,0 +1,14 @@
+# Build artifacts
+.stack-work/
+*.hi
+*.o
+*.dyn_hi
+*.dyn_o
+
+# Reports (generated, local-only)
+reports/
+
+# Editor
+*~
+*.swp
+.vscode/