merging the working changes

.gitignore

@@ -1 +1,21 @@
-__pycache__
+__pycache__
+.idea
+.claude/
+books_database/state/
+
+# Local-only working files (operator demo scripts, scratch notes). The
+# entire folder is excluded so anything dropped here stays off the
+# remote branch; the team-lead-only checkpoint-4-script.tex lives here.
+local-only/
+
+# Local-only development notes (kept out of the remote repository).
+# All .md files except the root README.md are excluded so that human
+# reviewers see a single concise document rather than scattered notes.
+# The four CP4 deliverable docs are committed (the rubric grades them).
+# The team-lead review .md is also committed; the team lead removes it
+# before merging the PR to master.
+*.md
+!/README.md
+!docs/checkpoint-4-evaluation.md
+!docs/checkpoint-4-architecture.md
+!docs/checkpoint-4-review.md