[IaC] Fix .gitignore — recursive __pycache__ exclusion + purge 22 cached .pyc files

Closes #1249

- Replace path-specific __pycache__ entries with recursive **/__pycache__/
- Add *.pyc and *.pyo globs
- Remove 22 tracked .pyc files from bin/, nexus/evennia_mempalace/,
  nexus/mempalace/, and nexus/mnemosyne/
- Reorganize .gitignore with section comments for clarity

.gitignore

@@ -1,10 +1,18 @@
+# === Python bytecode (recursive — covers all subdirectories) ===
+**/__pycache__/
+*.pyc
+*.pyo
+
+# === Node ===
 node_modules/
+
+# === Test artifacts ===
 test-results/
-nexus/__pycache__/
-tests/__pycache__/
-mempalace/__pycache__/
+test-screenshots/
+
+# === Tool configs ===
 .aider*
 
-# Prevent agents from writing to wrong path (see issue #1145)
+# === Path guardrails (see issue #1145) ===
+# Prevent agents from writing to wrong path
 public/nexus/
-test-screenshots/