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/templates/spec-template.md

@@ -0,0 +1,64 @@
+# Task: {title}
+
+## Goal
+
+What success looks like. One clear paragraph.
+
+## Non-Goals
+
+What is explicitly out of scope for this task.
+
+- {non-goal 1}
+- {non-goal 2}
+
+## Constraints
+
+Technical, time, or resource limitations.
+
+- {constraint 1}
+- {constraint 2}
+
+## Preferences
+
+Preferred patterns, frameworks, libraries, or approaches.
+
+- {preference 1}
+- {preference 2}
+
+## Non-Functional Requirements
+
+Performance, security, accessibility, scalability, or other quality attributes.
+
+- {NFR 1}
+- {NFR 2}
+
+## Success Criteria
+
+Falsifiable conditions that define "done". Each must be checkable by running a
+command or observing a specific system behavior.
+
+- {criterion — e.g., "All existing tests pass: `npm test` exits 0"}
+- {criterion — e.g., "New endpoint returns 200: `curl -s localhost:3000/api/health | jq .status` → "ok""}
+- {criterion — e.g., "No TypeScript errors: `npx tsc --noEmit` exits 0"}
+
+Do NOT write vague criteria:
+- "It should work" (not testable)
+- "The feature is implemented" (not falsifiable)
+- "Performance is acceptable" (no baseline given)
+
+## Prior Attempts
+
+What has been tried before and what happened. Leave blank if this is a fresh task.
+
+## Open Questions
+
+Unresolved items that may affect the plan. Flag these as assumptions if proceeding
+without answers.
+
+- {question 1}
+
+## Metadata
+
+- **Created:** {YYYY-MM-DD}
+- **Mode:** {interview | manual}
+- **Source:** {trekplan interview | user-provided}