ship(P07): v0.1.7 release backfill merged into milestone

- Fast-forward merge of phase/07-v0.1-backfill into milestone/v0.1-initial
- Annotated tag v0.1.7 created at dc67522
- Gitea release v0.1.7 published with orca-v0.1.7-linux-amd64.tar.gz
- Fix  ->  typo in release.sh notes block
  (unbound variable under set -u; surfaced on first end-to-end run
  of release.sh for v0.1.7). Patch is minimal and contained to the
  release-notes echo line.

scripts/release.sh

@@ -106,7 +106,7 @@ trap 'rm -f "$NOTES_FILE"' EXIT
 {
   echo "# Release $VERSION"
   echo ""
-  echo "_Built: $BUILD_TIME from $GIT_COMMIT_"
+  echo "_Built: $BUILD_TIME from $GIT_COMMIT"
   echo ""
 
   PREV_TAG="$(git describe --tags --abbrev=0 HEAD^ 2>/dev/null || echo "")"