Wire dotfiles/install.sh into all four setup scripts

[cpitzi]

Origin

Chris had just added the dotfiles/ capture directory (#63) with an
install.sh that deploys hand-tuned local configs (alacritty et al.) onto a
machine. He then asked to wire that installer into the provisioning scripts so
a freshly-provisioned or rebuilt machine restores those configs automatically,
without a manual post-provision step.

What changed

Each of the four setup-*.sh scripts now runs dotfiles/install.sh
automatically, as a non-fatal post-step immediately after the existing
claude-cost-export deploy — i.e. after the repo-clone step that lands the
workstation-bootstrap checkout containing install.sh:

if [[ -x "$WB_REPO/dotfiles/install.sh" ]]; then
  section "Local config files (dotfiles)"
  "$WB_REPO/dotfiles/install.sh" || warn "dotfiles install failed (non-fatal — re-run later)"
fi

The block is identical across all four scripts (per the keep-in-sync rule)
and deliberately mirrors the adjacent claude-cost-export precedent:

• -x-guarded — an older clone without dotfiles/install.sh skips cleanly.
• Reuses $WB_REPO — already defined in the preceding "Installing Scripts"
  step; no new clone, no duplicated logic.
• Non-fatal — a deploy failure is a warn, never a hard exit mid-setup.
• No step renumbering — like cost-export it's an unnumbered sub-section, so
  TOTAL_STEPS and every existing N/$TOTAL_STEPS header are untouched.

dotfiles/README.md updated: the "Not yet wired into setup-.sh" section
becomes "Deployed by setup-.sh".

Verification

• shellcheck --severity=warning clean on all four scripts.
• bash -n syntax check passes on all four.
• The inserted block is byte-identical across the four files (verified by grep).

Note (not in scope here)

The captured alacritty config pins working_directory = "/home/cpitzi" (an
absolute path, because alacritty doesn't expand ~). Auto-deploying it assumes
the target runs as user cpitzi. True for the homelab VMs and laptop; if a
future target uses a different username, that one value would need adjusting.
Flagging rather than fixing, since it's a property of the captured config, not
this wiring.

🤖 Generated with Claude Code