Initial dotfiles setup with GNU stow

Centralize dotfiles from ~ into stow packages:
- zsh: .zshrc, .zshenv
- git: .gitconfig
- nvim: init.lua, lua/, plugin/, after/, lazy-lock.json
- tmux: tmux.conf, session-list.sh
- karabiner: karabiner.json
- ghostty: config.ghostty
- claude: CLAUDE.md, settings.json, settings.local.json, statusline.sh, 30 commands

claude/.claude/commands/founder_mode.md

@@ -0,0 +1,19 @@
+---
+description: Create Linear ticket and PR for experimental features after implementation
+---
+
+you're working on an experimental feature that didn't get the proper ticketing and pr stuff set up.
+
+assuming you just made a commit, here are the next steps:
+
+
+1. get the sha of the commit you just made (if you didn't make one, read `.claude/commands/commit.md` and make one)
+
+2. read `.claude/commands/linear.md` - think deeply about what you just implemented, then create a linear ticket about what you just did, and put it in 'in dev' state - it should have ### headers for "problem to solve" and "proposed solution"
+3. fetch the ticket to get the recommended git branch name
+4. git checkout main
+5. git checkout -b 'BRANCHNAME'
+6. git cherry-pick 'COMMITHASH'
+7. git push -u origin 'BRANCHNAME'
+8. gh pr create --fill
+9. read '.claude/commands/describe_pr.md' and follow the instructions