Clean up bashrc: remove dead config, fix aliases, dedupe

[akan72]

Summary

Branch 1 of the dotfiles cleanup. Removes dead config and fixes broken aliases in bashrc.

• Remove dead config bare-repo alias
• Remove 10 unused Mercurial (hg) aliases
• Fix docker_rmi_dangling quoting (inner single quotes broke the alias)
• Replace dead postgresql@14 PATH with version-agnostic $(brew --prefix postgresql@17)/bin
• Remove dead sops PATH (~/Downloads/sops-3.7.2)
• Remove hardcoded Python 3.11 framework PATH
• Fix gdm/gdnm aliases: master → main
• Remove export TERM='xterm-256color'
• Remove duplicate NVM init block (also in zshrc)
• Remove duplicate cargo/env source (also in zshrc)
• Remove EDITOR export (zshrc owns it with SSH-aware logic)

Why & alternatives (from explanations.txt — Branch 1)

Change	Why	Alternatives
Remove config bare-repo alias	Dead code — symlink approach (assimilate.sh) is used, not bare-repo. Risk of accidentally tracking sensitive files in $HOME if ~/.cfg/ ever exists.	Keep it for a second dotfile strategy (unusual).
Remove Mercurial (hg) aliases	10 aliases for a VCS no longer used. Pure dead weight.	Keep if you still use hg.
Fix docker_rmi_dangling quoting	Inner single quotes inside outer single quotes break the alias — never worked as written.	Convert to a shell function.
Remove dead postgresql@14/14.6_1 PATH	Brewfile has postgresql@17 now — path doesn't exist on a fresh install.	Use $(brew --prefix postgresql@17)/bin (chosen) to be version-agnostic, or drop entirely and rely on brew link.
Remove ~/Downloads/sops-3.7.2 PATH	sops removed from Brewfile — PATH points to nothing.	Add sops back to Brewfile if still used.
Remove /Library/Frameworks/Python.framework/... PATH	Hardcoded Python 3.11 framework path. Brittle on upgrades.	Use pyenv/uv for version management.
Fix gdm/gdnm aliases	Reference master but repos default to main — broken in practice.	Make them dynamic via git symbolic-ref.
Remove export TERM='xterm-256color'	Root cause of the cursor debugging marathon. Hardcoding forces wrong terminfo regardless of terminal.	Set term = xterm-256color in Ghostty's config if an override is needed (already done there).
Remove duplicate NVM init	NVM init lived in both bashrc and zshrc; sourcing bashrc from zshrc ran it twice.	Single source of truth in shared.sh (Branch 3).
Remove duplicate cargo/env	Same double-source issue.	Single source of truth in shared.sh.
Remove EDITOR export	bashrc set EDITOR=nvim unconditionally; zshrc conditionally sets vim over SSH — inconsistent.	Let zshrc own it (richer logic).

---

Part of the sequential shell chain: Branch 1 → Branch 2 → Branch 3. Merge this first.