release: v0.8.1

Version bump across all seven workspace crates + path-dep constraints,
Cargo.lock, openapi.json, and the AGENTS.md surveyed version (also
restores the RFC-process row in the topic index that was dropped during
branch juggling). Release notes: docs/releases/v0.8.1.md.

Channel note: crates.io publication is deferred for this release — the
substrate is a rev-pinned Lance pre-release (git dependency), which
published crates cannot reference. publish-crates.yml gains a
self-healing guard that skips cleanly while the pin is a git dep and
resumes automatically when the dependency returns to a registry version
(Lance 9.0.0 stable → v0.9.0); a workflow_dispatch catch-up can then
publish any skipped tag. Binaries, Homebrew, and the installer ship
normally via release.yml.

.github/workflows/publish-crates.yml

@@ -36,6 +36,7 @@ jobs:
           echo "CARGO_REGISTRY_TOKEN is not set; skipping crates.io publish."
           echo "CARGO_PUBLISH_SKIP=1" >> "$GITHUB_ENV"
 
+
       - name: Resolve ref
         if: env.CARGO_PUBLISH_SKIP != '1'
         id: ref
@@ -50,6 +51,20 @@ jobs:
         with:
           ref: ${{ steps.ref.outputs.ref }}
 
+      # crates.io rejects git dependencies, so while the storage substrate is
+      # rev-pinned to a Lance pre-release (git dep in the workspace manifest)
+      # registry publication is deliberately deferred — binaries/Homebrew still
+      # ship from release.yml. This self-heals: the step stops matching the
+      # moment the dependency returns to a crates.io version (Lance 9 stable),
+      # and a workflow_dispatch catch-up run can then publish the skipped tag.
+      - name: Skip while the storage substrate is git-pinned
+        if: env.CARGO_PUBLISH_SKIP != '1'
+        run: |
+          if grep -qE '^lance = \{ git' Cargo.toml; then
+            echo "lance is git-pinned (pre-release substrate); deferring crates.io publish for this tag."
+            echo "CARGO_PUBLISH_SKIP=1" >> "$GITHUB_ENV"
+          fi
+
       - name: Install Linux dependencies
         if: env.CARGO_PUBLISH_SKIP != '1'
         run: |