feat: add R2 file sharing tool with environment configuration

- Add share.ts CLI tool for uploading files to R2 with clipboard integration
- Configure R2 credentials across all shell environments (fish, bash, nushell)
- Add shell abbreviations for claude opus and share commands
- Refine claude-usage terminology (quota → limit, behind → under)

home/dot_config/fish/conf.d/abbr.fish.tmpl

@@ -30,7 +30,9 @@ abbr -a romanlog "ssh roman 'tail -F /var/log/syslog' --lines 100"
 # Other aliases
 abbr -a oc 'opencode'
 abbr -a cl 'claude'
+abbr -a cope 'claude --model opus'
 abbr -a gpt 'chatgpt'
+abbr -a share 'share.ts'
 abbr -a copilot 'gh copilot'
 abbr -a suggest 'gh copilot suggest -t shell'
 abbr -a spt 'spotify_player'