chore: expand .gitignore with Lua, Vim, and AI session patterns

Replaces the minimal hand-written ignore list with generated gitignore.io
patterns for Lua and Vim, plus a boilerplate template covering OS artefacts,
temp directories, and AI session/rules files (CLAUDE.md, GEMINI.md, .claud*,
.gemin*, .remember, etc.).

.gitignore

@@ -1,5 +1,3 @@
-/.claude_session
-
 # Plugin installs (managed by vim.pack)
 /pack/
 
@@ -25,11 +23,155 @@
 # Logs
 *.log
 
-# OS
+# id: gi-patterns-aa0d0d1d58f24039fa0491e40c78bb9f
+# Created by https://www.toptal.com/developers/gitignore/api/lua
+# Edit at https://www.toptal.com/developers/gitignore?templates=lua
+
+### Lua ###
+# Compiled Lua sources
+luac.out
+
+# luarocks build files
+*.src.rock
+*.zip
+*.tar.gz
+
+# Object files
+*.o
+*.os
+*.ko
+*.obj
+*.elf
+
+# Precompiled Headers
+*.gch
+*.pch
+
+# Libraries
+*.lib
+*.a
+*.la
+*.lo
+*.def
+*.exp
+
+# Shared objects (inc. Windows DLLs)
+*.dll
+*.so
+*.so.*
+*.dylib
+
+# Executables
+*.exe
+*.out
+*.app
+*.i*86
+*.x86_64
+*.hex
+
+
+# End of https://www.toptal.com/developers/gitignore/api/lua
+
+# id: gi-patterns-be86a7264ac20631fa0112bcaff396d7
+# Created by https://www.toptal.com/developers/gitignore/api/vim
+# Edit at https://www.toptal.com/developers/gitignore?templates=vim
+
+### Vim ###
+# Swap
+[._]*.s[a-v][a-z]
+!*.svg  # comment out if you don't need vector files
+[._]*.sw[a-p]
+[._]s[a-rt-v][a-z]
+[._]ss[a-gi-z]
+[._]sw[a-p]
+
+# Session
+Session.vim
+Sessionx.vim
+
+# Temporary
+.netrwhist
+*~
+# Auto-generated tag files
+tags
+# Persistent undo
+[._]*.un~
+
+# End of https://www.toptal.com/developers/gitignore/api/vim
+
+# id: gitig-boilerplate-129366cbf5c6513e388d0725c2e4923b
+#   ╭──────────────────────────────────────────────────────────╮
+#   │              GitIgnore Boilerplate Template              │
+#   ╰──────────────────────────────────────────────────────────╯
+#
+#   ──────────────────── OS-Generated Files ────────────────────
+# automatic backup files created by some editors (e.g., Vim, Emacs)
+*~
+
+# temporary files created if a process still has a handle to a deleted file
+.fuse_hidden*
+
+# KDE directory preferences
+.directory
+
+# MacOS junk
 .DS_Store
 Thumbs.db
 
-# AI assistant files
+# Linux trash folder which might appear on any partition or disk
-CLAUDE.md
+.Trash-*
-GEMINI.md
+
-.gemini_session
+# files created when an open file is removed but is still being accessed
+.nfs*
+
+#   ─────────────────── Debug/Temporary/Testing ────────────────
+# Matches OLD / .OLD
+[Oo][Ll][Dd]/
+.[Oo][Ll][Dd]/
+
+# Matches DISABLE / .DISABLE
+[Dd][Ii][Ss][Aa][Bb][Ll][Ee]/
+.[Dd][Ii][Ss][Aa][Bb][Ll][Ee]/
+
+# Matches DISABLED / .DISABLED
+[Dd][Ii][Ss][Aa][Bb][Ll][Ee][Dd]/
+.[Dd][Ii][Ss][Aa][Bb][Ll][Ee][Dd]/
+
+# Matches DEBUG / .DEBUG
+[Dd][Ee][Bb][Uu][Gg]/
+.[Dd][Ee][Bb][Uu][Gg]/
+
+# Matches TMP / .TMP
+[Tt][Mm][Pp]/
+.[Tt][Mm][Pp]/
+
+# Matches TEMP / .TEMP
+[Tt][Ee][Mm][Pp]/
+.[Tt][Ee][Mm][Pp]/
+
+# Matches TEMPORARY / .TEMPORARY
+[Tt][Ee][Mm][Pp][Oo][Rr][Aa][Rr][Yy]/
+.[Tt][Ee][Mm][Pp][Oo][Rr][Aa][Rr][Yy]/
+
+# Matches TESTING / .TESTING
+[Tt][Ee][Ss][Tt][Ii][Nn][Gg]/
+.[Tt][Ee][Ss][Tt][Ii][Nn][Gg]/
+
+#   ─────────────────── AI Sessions and Rules ──────────────────
+# Matches CLAUDE.md, .claud*, etc.
+[Cc][Ll][Aa][Uu][Dd][Ee].[Mm][Dd]
+.[Cc][Ll][Aa][Uu][Dd]*
+
+# Matches GEMINI.md, .gemin*, etc.
+[Gg][Ee][Mm][Ii][Nn][Ii].[Mm][Dd]
+.[Gg][Ee][Mm][Ii][Nn]*
+
+# Matches ANTIGRAVITY.md, .antigrav*, etc.
+[Aa][nN][Tt][Ii][Gg][Rr][Aa][Vv][Ii][Tt][Yy].[Mm][Dd]
+.[Aa][Nn][Tt][Ii][Gg][Rr][Aa][Vv]*
+
+# Matches AGENTS.md, .remember, etc.
+[Aa][Gg][Ee][Nn][Tt][Ss].[Mm][Dd]
+.[Rr][Ee][Mm][Ee][Mm][Bb][Ee][Rr]
+
+# ──────────────────────────────────────────────────────────────