feat(voyage)!: marketplace handoff — rename plugins/ultraplan-local to plugins/voyage [skip-docs]

Session 5 of voyage-rebrand (V6). Operator-authorized cross-plugin scope.

- git mv plugins/ultraplan-local plugins/voyage (rename detected, history preserved)
- .claude-plugin/marketplace.json: voyage entry replaces ultraplan-local
- CLAUDE.md: voyage row in plugin list, voyage in design-system consumer list
- README.md: bulk rename ultra*-local commands -> trek* commands; ultraplan-local refs -> voyage; type discriminators (type: trekbrief/trekreview); session-title pattern (voyage:<command>:<slug>); v4.0.0 release-note paragraph
- plugins/voyage/.claude-plugin/plugin.json: homepage/repository URLs point to monorepo voyage path
- plugins/voyage/verify.sh: drop URL whitelist exception (no longer needed)

Closes voyage-rebrand. bash plugins/voyage/verify.sh PASS 7/7. npm test 361/361.

plugins/voyage/TRADEMARKS.md

@@ -0,0 +1,42 @@
+# Trademarks
+
+## Third-party trademarks
+
+**Claude** and **Claude Code** are trademarks of Anthropic, PBC.
+**`/ultraplan`** and **`/ultrareview`** are named features of Anthropic's
+Claude Code product.
+
+Voyage is an independent open-source project. It is not affiliated with,
+endorsed by, or sponsored by Anthropic, PBC. The Voyage project receives no
+support, approval, or authorization from Anthropic for any aspect of this
+software.
+
+Voyage uses the names "Claude" and "Claude Code" solely to identify the
+platform within which Voyage operates. This is nominative use: the platform
+cannot be identified without its name, only as much of the name is used as is
+necessary, and no affiliation or endorsement is implied.
+
+Voyage does not use, integrate with, replicate, or compete with Anthropic's
+`/ultraplan` or `/ultrareview` features. The previous command names
+`/ultraplan-local` and `/ultrareview-local` were retired proactively to
+remove any potential confusion with Anthropic's own feature namespace.
+Voyage's commands are prefixed `/trek*` and are entirely independent of any
+Anthropic-named feature.
+
+## Voyage's own marks
+
+**Voyage** and the **`/trek*`** command prefix are names used by this
+project. They are not registered trademarks. Nothing in this file grants
+permission to use "Voyage" or "/trek*" in any way that suggests this project
+is the source of software it did not produce.
+
+## Trademarks of other parties
+
+Any other trademarks referenced in Voyage's documentation belong to their
+respective owners and are used for identification purposes only. Their use
+does not imply endorsement of Voyage by those owners, nor endorsement of
+those owners' products or services by the Voyage project.
+
+## Contact
+
+Trademark questions may be raised via the project's issue tracker.