build(release): track single root product version in release-please

Veect is a hosted SaaS deploying continuously (ADR-027), so release-please
now tracks only the root package with plain v* tags. Drops the five
packages/* entries ahead of story 03's feature deletions so ADR-021's
commit -> release automation keeps working through them.

include-component-in-tag is set to false rather than removed: the
upstream default is true and the node strategy derives a component from
package.json, so literal key removal would keep component-prefixed tags
(template-vertical-v*) instead of the wanted plain v* tags.

Pre-1.0 bump policy (bump-patch-for-minor-pre-major) and changelog
sections are retained. The release workflow's SBOM steps already use the
tag-format-agnostic tag_name output; only its header comment needed
updating. Per-feature CHANGELOG.md files stay on disk untracked by
release-please until story 03 deletes them with their packages.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016j8z4VHjedXDTjEDNg7qHK

.release-please-manifest.json

@@ -1,8 +1,3 @@
 {
-  ".": "0.1.0",
-  "packages/auth": "0.1.0",
-  "packages/blog": "0.1.0",
-  "packages/media": "0.1.0",
-  "packages/marketing-pages": "0.1.0",
-  "packages/navigation": "0.1.0"
+  ".": "0.1.0"
 }