release: one-command build, sign, publish, and attach — plus dormant workflow (#52)

Implements the full release flow: a single script builds both deb and rpm
packages, signs the RPM payload, generates and clearsigns SHA256SUMS, uploads
to the Gitea package registry (deb to bookworm/jammy/noble pools, rpm to the
fenris group), creates a Gitea release entry with notes, and attaches all
artifacts.

Key changes:
- scripts/release.sh: new release script with --dry-run and --publish modes
- tests/test_release.py: 32 structural tests (dry-run output, filenames,
  revision bumping, bare tag prevention, CI workflow, Makefile targets)
- Makefile: added release-run and release-dry-run targets
- .gitea/workflows/release.yml: extended dormant workflow with signing,
  upload, release creation, and artifact attachment (idempotent re-runs)
- docs/install/signing-key-ceremony.md: added one-time live probe section
  documenting throwaway package publish, apt/dnf verification, and cleanup

Acceptance criteria met:
- One release command performs build, sign, publish, and attach
- Dry-run mode prints every command; tests assert output without network
- Revision bumping on 409 (same-version rebuilds increment release number)
- Dormant CI workflow replicates the flow (queues harmlessly without runner)
- Live probe documented with throwaway package end-to-end
- No bare tags: release API creates tag atomically with release entry

Co-authored-by: CommandCodeBot <noreply@commandcode.ai>

docs/install/signing-key-ceremony.md

@@ -132,3 +132,99 @@ verification is manual for downloaded assets:
 gpg --verify SHA256SUMS.asc SHA256SUMS
 sha256sum -c SHA256SUMS
 ```
+
+## One-time live probe
+
+Before the first real release, verify the full registry path end-to-end with a
+throwaway package. This confirms apt/dnf metadata generation, signature
+verification, and consumer setup work as a real consumer would experience them.
+
+### Setup
+
+```bash
+# Create a throwaway package name to avoid polluting fenris metadata
+PROBE_NAME="fenris-regtest"
+PROBE_VERSION="0.0.1"
+```
+
+### Publish
+
+```bash
+# Build a throwaway deb and rpm (use the existing nfpm config with a dummy name)
+# Or use a pre-built package — the probe tests the registry path, not the build
+
+# Upload deb to all codename pools
+for CODENAME in bookworm jammy noble; do
+  curl --fail -X PUT \
+    -u "xavierk:${GITEA_TOKEN}" \
+    -T "dist/${PROBE_NAME}_${PROBE_VERSION}_amd64.deb" \
+    "https://git.bongbetic.com/api/packages/xavierk/debian/pool/${CODENAME}/main/upload"
+done
+
+# Upload rpm
+curl --fail -X PUT \
+  -u "xavierk:${GITEA_TOKEN}" \
+  -T "dist/${PROBE_NAME}-${PROBE_VERSION}-1.x86_64.rpm" \
+  "https://git.bongbetic.com/api/packages/xavierk/rpm/fenris/upload"
+```
+
+### Verify apt metadata (Debian/Ubuntu consumer perspective)
+
+```bash
+# On a Debian/Ubuntu machine:
+sudo mkdir -p /etc/apt/keyrings
+sudo curl -fsSL https://git.bongbetic.com/api/packages/xavierk/debian/repository.key \
+  | sudo gpg --dearmor -o /etc/apt/keyrings/gitea-xavierk.asc
+
+echo "deb [signed-by=/etc/apt/keyrings/gitea-xavierk.asc] https://git.bongbetic.com/api/packages/xavierk/debian bookworm main" \
+  | sudo tee /etc/apt/sources.list.d/fenris.list
+
+sudo apt update
+apt show ${PROBE_NAME}           # metadata present, correct version
+apt install --dry-run ${PROBE_NAME}  # dependency resolution works
+
+# Verify InRelease signature
+apt-key list 2>/dev/null || gpg --no-default-keyring --keyring /etc/apt/keyrings/gitea-xavierk.asc --list-keys
+```
+
+### Verify dnf metadata (Fedora consumer perspective)
+
+```bash
+# On a Fedora machine:
+sudo dnf config-manager --add-repo https://git.bongbetic.com/xavierk/Fenris/raw/branch/main/packaging/fenris.repo
+# Or use Gitea's auto-generated repo for the probe:
+sudo dnf config-manager --add-repo https://git.bongbetic.com/api/packages/xavierk/rpm/fenris.repo
+
+dnf info ${PROBE_NAME}          # metadata present, correct version
+dnf install --assumeno ${PROBE_NAME}  # dependency resolution works
+
+# Verify rpm signature
+rpm -q --scripts ${PROBE_NAME}  # no scripts (throwaway)
+```
+
+### Verify checksums and clearsign
+
+```bash
+# Download from release assets or local build
+gpg --verify SHA256SUMS.asc SHA256SUMS
+sha256sum -c SHA256SUMS
+```
+
+### Cleanup
+
+```bash
+# Delete the throwaway packages from the registry
+for CODENAME in bookworm jammy noble; do
+  curl --fail -X DELETE \
+    -u "xavierk:${GITEA_TOKEN}" \
+    "https://git.bongbetic.com/api/packages/xavierk/debian/pool/${CODENAME}/main/${PROBE_NAME}/${PROBE_VERSION}/amd64"
+done
+
+curl --fail -X DELETE \
+  -u "xavierk:${GITEA_TOKEN}" \
+  "https://git.bongbetic.com/api/packages/xavierk/rpm/fenris/${PROBE_NAME}/${PROBE_VERSION}/x86_64"
+
+# Remove test source list on consumer machines
+sudo rm /etc/apt/sources.list.d/fenris.list
+sudo apt update
+```