Split release into per-track packages

Each shippable artifact (prb, probod server group, probod-bootstrap,
@probo/n8n-nodes-probo, @probo/cookie-banner) now has its own version
file, its own CHANGELOG.md, its own annotated-tag scheme of the form
<track>/v<version>, and its own GitHub Actions release workflow. The
unified release.yaml is removed; the unified CHANGELOG.md becomes a
short index pointing at each per-track file, with the prior history
preserved in CHANGELOG.archive.md.

Probod's CHANGELOG carries the post-split monorepo releases (0.174.0
through 0.181.0) so the server-group history stays continuous and the
probod docker image keeps its existing version line.

contrib/claude/release.md is split into contrib/claude/release/ with
one entrypoint per track plus a README that drives the agent: detect
which tracks have user-facing commits since their last tag and skip
tracks with no relevant changes, so a release request never tags an
unchanged track. The cookie-banner and n8n-node entrypoints add an
explicit npm run build step after the version bump (build.mjs bakes
package.json's version into __SDK_VERSION__) so compile errors and
package-lock.json updates are caught before tagging.

Signed-off-by: Bryan Frimin <bryan@getprobo.com>

cmd/prb/CHANGELOG.md

@@ -0,0 +1,11 @@
+# Changelog
+
+All notable changes to the `prb` CLI will be documented in this file.
+
+## Unreleased
+
+## [0.173.0] - 2026-04-27
+
+### Changed
+
+- First per-package release. Prior history is in the archived monorepo [CHANGELOG.archive.md](../../CHANGELOG.archive.md).

cmd/prb/VERSION

@@ -0,0 +1 @@
+0.173.0