chore: add sethLabels deployment-fork scaffold

Adds Seth's homelab convention files on top of upstream glabels-qt master:
CLAUDE.md (project instructions), IDEA.md (brief), DECISIONS.md (decision
log, empty), and the kickoff handoff under .claude/handoffs/. Appends a
clearly-marked sethLabels section to .gitignore for .backup/, the
GITEA_API.md symlink, .env files, and handoff drafts.

This is the only non-upstream commit on main. All preceding history is
authored by the glabels.org team (Jaye Evins et al.) and untouched.
Future upstream merges should fast-forward or rebase cleanly since the
scaffold lives in distinct files at repo root.

No source-code changes. License unchanged (GPL-3.0).

CLAUDE.md

@@ -0,0 +1,27 @@
+# sethLabels
+
+> Deployment fork of glabels-qt — Qt label designer/printer, packaged for Seth's homelab.
+
+## Start Here
+
+**Read the latest handoff first:** `.claude/handoffs/` (most recent file).
+It has session state, in-progress work, and ordered next steps.
+
+Then check `IDEA.md` for the project brief and `DECISIONS.md` for settled choices.
+
+## Project Identity
+
+sethLabels is a thin deployment fork of [glabels-qt](https://github.com/j-evins/glabels-qt). Upstream is the real project — this fork's job is to keep a known-good build recipe, any deployment glue (packaging, install paths, default templates), and any local patches in one place, while staying close enough to upstream `master` that periodic rebases stay cheap.
+
+## Current State
+
+- **Phase:** ideation (just scaffolded — no code, no upstream pull yet)
+- **Repo:** not yet (will live at `git.sethpc.xyz/Seth/sethLabels` once first commit lands)
+- **Deploy target:** steel141 (Debian 13) — primary; CT for headless print serving optional/later
+- **Upstream:** https://github.com/j-evins/glabels-qt (GPL-3.0, Qt + CMake + C++)
+
+## Conventions
+
+- This is a **fork**, not a from-scratch rewrite. Pull upstream first; only patch what we need to change. Keep diffs surgical.
+- Preserve upstream license (GPL-3.0) and copyright headers.
+- See `~/bin/CLAUDE.md` for global homelab conventions (gitea CLI, conventional commits, credentials handling).