chore: prettify and sort .gitignore

Groups patterns by category (Python cache, venvs, build artifacts, IDE,
OS, logs, env files, generated output, project scratch, Conductor) with
labeled comment headers, sorts within each group, and adds trailing
slashes to directory patterns for clarity.

Also removes the stale `*.cpython-312.pyc\`` line which had a literal
backtick typo (so it wasn't matching anything) and is already covered
by `*.pyc`.

No behavior changes anyone would notice from the rule set.

Signed-off-by: lelia <2418071+lelia@users.noreply.github.com>

Author: lelia

.gitignore

@@ -1,33 +1,52 @@
-.idea
-venv
-.venv
-.venv-test
-build
-dist
+# --- Python bytecode / cache ---
+*.pyc
+__pycache__/
+.coverage
+
+# --- Virtual environments ---
+venv/
+.venv/
+.venv-test/
+Pipfile
+
+# --- Build / packaging ---
 *.build
 *.dist
-*.egg-info
-*.env
-run_container.sh
+*.egg-info/
+bin/
+build/
+dist/
 *.zip
-bin
-scripts/*.py
+
+# --- Editor / IDE ---
+.idea/
+
+# --- OS ---
+.DS_Store
+
+# --- Logs ---
+logs/
+
+# --- Env files ---
+*.env
+.env.local
+
+# --- Generated output ---
 *.json
-*.sarif
 !tests/**/*.json
 !examples/config/*.json
+*.sarif
 markdown_overview_temp.md
 markdown_security_temp.md
-.DS_Store
-*.pyc
-test.py
-*.cpython-312.pyc`
+
+# --- Project-specific scratch ---
+ai_testing/
 file_generator.py
-.coverage
-.env.local
-Pipfile
+run_container.sh
+scripts/*.py
 test/
-logs
-ai_testing/
+test.py
 verify_find_files_lazy_loading.py
+
+# --- Conductor workspace ---
 .context/