diff --git a/plugins/ultraplan-local/MIGRATION.md b/plugins/ultraplan-local/MIGRATION.md
index 5d42fd8..cec0a12 100644
--- a/plugins/ultraplan-local/MIGRATION.md
+++ b/plugins/ultraplan-local/MIGRATION.md
@@ -1,284 +1,12 @@
-# Migration guide: v1.x → v2.0.0
-
-v2.0.0 is a breaking release. This guide walks through everything that changed
-and how to update your workflow.
-
-## TL;DR
-
-| You used to run | Now run |
-|-----------------|---------|
-| `/ultraplan-local "Add auth"` | `/ultrabrief-local "Add auth"` → `/ultraplan-local --project
` |
-| `/ultraplan-local --spec spec.md` | Convert spec → brief, then `/ultraplan-local --brief brief.md` |
-| `/ultraresearch-local "..."` | Same (still works). Add `--project ` to land results inside a project dir. |
-| `/ultraexecute-local plan.md` | Same (still works). Add `--project ` to use project paths. |
-
-## What changed and why
-
-### 1. Four commands, not three
-
-v1.x had three commands. v2.0 introduces `/ultrabrief-local` as a first-class
-step:
-
-```
-/ultrabrief-local → brief.md (NEW in v2.0)
-/ultraresearch-local → research briefs
-/ultraplan-local → plan.md
-/ultraexecute-local → progress.json
-```
-
-**Why:** In v1, the interview was buried inside `/ultraplan-local`. That made
-it impossible to review the captured intent before research + planning started.
-With `/ultrabrief-local` as a separate step:
-
-- The **task brief** is a reviewable, editable artifact before you spend a
- single Opus token on planning.
-- Research topics are declared explicitly, with clear scope and confidence
- requirements.
-- You can re-plan from the same brief multiple times (e.g., after research
- reveals a new constraint).
-
-### 2. Project directory as the single source of truth
-
-All pipeline artifacts now live in one directory:
-
-```
-.claude/projects/2026-04-18-jwt-auth/
-├── brief.md ← /ultrabrief-local
-├── research/
-│ ├── 01-jwt-best-practices.md ← /ultraresearch-local --project
-│ └── 02-existing-auth-code.md
-├── plan.md ← /ultraplan-local --project
-├── sessions/ ← /ultraplan-local --decompose
-└── progress.json ← /ultraexecute-local --project
-```
-
-`--project ` works on `/ultraresearch-local`, `/ultraplan-local`, and
-`/ultraexecute-local`. Pass it once and each command writes to the right
-place automatically.
-
-**Legacy paths still work.** If you don't pass `--project`, commands write to
-the v1.x locations (`.claude/research/`, `.claude/plans/`, etc.). Existing
-v1 plans execute unchanged.
-
-### 3. `/ultraplan-local` requires a brief
-
-**v1.x:**
-```bash
-/ultraplan-local "Add authentication with JWT"
-# ...interview happens inside the command
-```
-
-**v2.0:**
-```bash
-/ultraplan-local "Add authentication with JWT"
-# ERROR: /ultraplan-local requires --brief or --project.
-# Run /ultrabrief-local first.
-```
-
-You must pass one of:
-- `--project ` — reads `{dir}/brief.md` + any `{dir}/research/*.md`
-- `--brief ` — reads a specific brief file
-
-**Why:** Separating interview from planning is a deliberate architectural choice.
-See CHANGELOG.md `[2.0.0]` → Rationale.
-
-### 4. `--spec` is removed
-
-**v1.x:**
-```bash
-/ultraplan-local --spec .claude/ultraplan-spec-2026-04-01-auth.md
-```
-
-**v2.0:** The `--spec` flag is gone. You can either:
-
-**Option A (recommended):** Re-run `/ultrabrief-local` to capture intent fresh.
-```bash
-/ultrabrief-local "Add authentication with JWT"
-```
-
-**Option B:** Convert an old spec to a brief manually. The two formats are
-similar but a brief has two additional required sections: `## Intent` and
-`## Research Plan`.
-
-Minimal conversion template — take your old spec and add:
-
-```markdown
----
-type: ultrabrief
-brief_version: 2.0
-created: 2026-04-18
-task: "{copy one-line description from your spec}"
-slug: {your-slug}
-project_dir: .claude/projects/2026-04-18-{slug}/
-research_topics: 0
-research_status: skipped
-auto_research: false
-interview_turns: 0
-source: manual
----
-
-# Task: {Your title}
-
-## Intent
-
-*New section in v2.0. 3-5 sentences on why this matters.*
-
-{Write why this task exists — motivation, user need, strategic context.}
-
-## Goal
-
-{Copy your spec's goal/overview here — 1 paragraph.}
-
-## Non-Goals
-
-{Copy from spec. Or list explicitly what's out of scope.}
-
-## Constraints / Preferences / NFRs
-
-{Copy from spec's constraints section.}
-
-## Success Criteria
-
-{Copy from spec. Ensure each is falsifiable — a command or observation.}
-
-## Research Plan
-
-*New section in v2.0. Declare research topics upfront.*
-
-No external research needed. (Or list N topics if you have them.)
-
-## Open Questions / Assumptions
-
-{Copy from spec, or list any assumptions you're making.}
-
-## Prior Attempts
-
-None — fresh task. (Or describe what was tried before.)
-```
-
-Save this as `brief.md` inside your project directory, then:
-
-```bash
-/ultraplan-local --project .claude/projects/2026-04-18-{slug}
-```
-
-### 5. `spec-reviewer` → `brief-reviewer`
-
-The review agent that runs before exploration has been renamed and expanded:
-
-| | v1.x | v2.0 |
-|--|------|------|
-| File | `agents/spec-reviewer.md` | `agents/brief-reviewer.md` |
-| Dimensions | 4 (completeness, consistency, testability, scope clarity) | 5 (+ Research Plan validity) |
-| Input | `Spec file: ` | `Brief file: ` |
-
-The new 5th dimension checks that every research topic has a valid research
-question (ends in `?`), declares `Required for plan steps:` and
-`Confidence needed:`, and — if `auto_research: true` — verifies the actual
-research briefs exist in `{project_dir}/research/`.
-
-## Step-by-step migration for an in-flight v1 project
-
-Say you have:
-
-```
-.claude/ultraplan-spec-2026-03-20-auth.md # old spec
-.claude/plans/ultraplan-2026-03-20-auth.md # old plan
-```
-
-### Option 1: Keep existing plan, skip re-planning
-
-Old plans execute unchanged in v2.0. Just run:
-
-```bash
-/ultraexecute-local .claude/plans/ultraplan-2026-03-20-auth.md
-```
-
-No migration needed. Legacy plans remain valid.
-
-### Option 2: Re-plan with v2 tooling
-
-1. Create the project directory:
- ```bash
- mkdir -p .claude/projects/2026-04-18-auth/research
- ```
-
-2. Convert spec → brief using the template above. Save as:
- ```
- .claude/projects/2026-04-18-auth/brief.md
- ```
-
-3. (Optional) Copy any prior research briefs into `research/`:
- ```bash
- cp .claude/research/ultraresearch-2026-03-*.md \
- .claude/projects/2026-04-18-auth/research/01-prior-research.md
- ```
-
-4. Re-plan:
- ```bash
- /ultraplan-local --project .claude/projects/2026-04-18-auth
- ```
-
-5. Execute:
- ```bash
- /ultraexecute-local --project .claude/projects/2026-04-18-auth
- ```
-
-### Option 3: Start fresh with v2 workflow
-
-For new work, skip the conversion:
-
-```bash
-/ultrabrief-local "Add authentication with JWT"
-# Answer interview questions. Identifies research topics.
-
-# Manual path:
-/ultraresearch-local --project .claude/projects/2026-04-18-auth --external "JWT best practices?"
-/ultraplan-local --project .claude/projects/2026-04-18-auth
-/ultraexecute-local --project .claude/projects/2026-04-18-auth
-
-# OR auto path — choose "Auto" when /ultrabrief-local asks.
-# Research + planning run in foreground, return when plan.md is ready.
-/ultraexecute-local --project .claude/projects/2026-04-18-auth
-```
-
-## What still works unchanged
-
-- `/ultraresearch-local ` without `--project` — still writes to
- `.claude/research/ultraresearch-{date}-{slug}.md`
-- `/ultraexecute-local ` — executes any v1 or v2 plan
-- `/ultraplan-local --decompose ` — works on both v1 and v2 plans
-- `/ultraplan-local --export ` — works on both v1 and v2 plans
-- All `--fg`, `--quick`, `--resume`, `--dry-run`, `--validate`, `--step`,
- `--session` flags — unchanged behavior
-
-## What breaks without a migration
-
-- `/ultraplan-local ` without `--brief` or `--project` — errors out
-- `/ultraplan-local --spec ` — `--spec` flag no longer exists
-- Any script that references `agents/spec-reviewer.md` — file is deleted
-- Planning orchestrator invocations that pass `Spec file: ` — now
- expects `Brief file: `
-
-## FAQ
-
-**Q: Do I have to migrate old plans?**
-A: No. Old plans execute unchanged. Migration is only needed if you want to
-re-plan.
-
-**Q: Can I keep using the old spec files?**
-A: Yes, but not with `/ultraplan-local`. You can continue referring to them
-manually, but to re-plan in v2 you must convert them to briefs (see Option 2
-above).
-
-**Q: What if I don't want an interview?**
-A: Write `brief.md` directly using the template in
-`templates/ultrabrief-template.md`. Set `source: manual` in the frontmatter.
-
-**Q: Can I run `/ultraplan-local` with just a research brief, no task brief?**
-A: No. A task brief is required. The task brief captures *intent*; a research
-brief captures *information about a topic*. These are not interchangeable.
-
-**Q: My `.claude/projects/` directory doesn't exist. Should I create it?**
-A: `/ultrabrief-local` creates it automatically when you run it. You only need
-to create it manually if you're converting an old spec (Option 2 above).
+# Migration
+
+v3.x → v4.0.0 is a rebrand. All command names changed:
+`/ultrabrief-local` → `/trekbrief`, `/ultraresearch-local` → `/trekresearch`,
+`/ultraplan-local` → `/trekplan`, `/ultraexecute-local` → `/trekexecute`,
+`/ultrareview-local` → `/trekreview`, `/ultracontinue-local` → `/trekcontinue`,
+`/ultraplan-end-session-local` → `/trekendsession`. The plugin is now
+named `voyage`. Re-fork from main if upgrading. There is no migration
+path — see `GOVERNANCE.md` for the fork-and-own model.
+
+Prior version migration notes (v1→v2, v2→v3) are preserved in
+`CHANGELOG.md` only.