Merge origin/main: preserve relic system and diagnostics updates

.gitignore

@@ -19,24 +19,22 @@ tools/*.mjs
 !mengsan/tools/check-sts2-relics.mjs
 !mengsan/tools/write-sts2-relics-report.mjs
 
-# Local updater downloads and runtime logs
 /.update_tmp/
+/.planning/
 /mengsan/logs/
+/logs/
 *.log
 
-# Local credentials; keep shareable environment templates
 .env
 .env.*
 !.env.example
 !.env.sample
 !.env.template
 
-# Dependency and interpreter caches
 node_modules/
 __pycache__/
 *.pyc
 
-# Editor temporary files and OS metadata
 *.tmp
 *.bak
 *.swp