Seed bootapi-images: AlmaLinux node rootfs build

Builds the AlmaLinux 9 node rootfs tarball bootapi's image-based provisioning
(liveimg) unpacks, and on a v* tag publishes almalinux9-node-<ver>.tar.zst to the
artifactapi rootfs-images repo. Moved out of bootapi-templates (which stays
templates-only) per review on bootapi-templates#3.

- packages.txt (bake list) + scripts/build-rootfs.sh (dnf --installroot -> tar.zst).
- .woodpecker: pre-commit + shellcheck (PR); build+upload on v* tag.
- Makefile (build/lint/patch|minor|major).

Claude-Session: https://claude.ai/code/session_015ur3i7D2azsMAWTSVABApv

.pre-commit-config.yaml

@@ -0,0 +1,20 @@
+repos:
+  - repo: https://github.com/pre-commit/pre-commit-hooks
+    rev: v5.0.0
+    hooks:
+      - id: trailing-whitespace
+      - id: end-of-file-fixer
+      - id: check-yaml
+      - id: check-added-large-files
+      - id: check-merge-conflict
+
+  - repo: https://github.com/adrienverge/yamllint
+    rev: v1.35.1
+    hooks:
+      - id: yamllint
+        args: [-c, .yamllint.yaml]
+
+  - repo: https://github.com/shellcheck-py/shellcheck-py
+    rev: v0.10.0.1
+    hooks:
+      - id: shellcheck