feat(voyage)!: bulk content rewrite ultra -> voyage/trek prose [skip-docs]

Sed-pipeline (16 patterns, longest-match-first) sweeper residuelle ultra*-treff
i prose, command-narrativ, agent-prompts, hook-kommentarer, doc-prosa.

Pipeline-utvidelser fra V4-prompten:
- BSD-syntax [[:<:]]ultra[[:>:]] istedenfor \bultra\b (BSD sed mangler \b)
- 6 compound-patterns for ultraplan/ultraexecute/ultraresearch/ultrabrief/
  ultrareview/ultracontinue uten -local-suffiks
- ultra*-stats glob -> trek*-stats glob
- Linje-eksklusjon redusert til ultra-cc-architect (Q8); session-state-
  eksklusjonen var over-protektiv
- File-eksklusjon utvidet til settings.json, package.json, plugin.json,
  hele .claude/-treet (gitignored + V5-territorium)

Q8-undantak holdt: architecture-discovery.mjs + project-discovery.mjs urort.
Filnavn-konvensjon holdt: .session-state.local.json + *.local.* preservert.

Manuell narrative-fix: tests/lib/agent-frontmatter.test.mjs linje 10
mangled "/ultra*-local" til "/voyage*-local" (ingen slik kommando finnes);
korrigert til "/trek*".

Residualer utenfor scope (V5 handterer): package.json + .claude-plugin/
plugin.json (Step 12-14 versjons-bump). .claude/* er gitignored
spec-historikk med tilsiktet BEFORE/AFTER-narrativ.

Part of voyage-rebrand session 3 (Wave 4 / Step 10).

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

plugins/ultraplan-local/templates/headless-launch-template.md

@@ -7,7 +7,7 @@ for headless execution of decomposed sessions.
 
 ```bash
 #!/usr/bin/env bash
-# Headless launch script — generated by ultraplan-local
+# Headless launch script — generated by trekplan
 # Master plan: {plan_path}
 # Generated: {date}
 # Sessions: {total_sessions} ({parallel_count} parallel, {sequential_count} sequential)
@@ -24,7 +24,7 @@ WORKTREE_BASE="{session_dir}/worktrees"
 mkdir -p "$LOG_DIR" "$WORKTREE_BASE"
 
 # Disable git's optional locks during parallel worktree ops (research/02 R2;
-# GH #47721). Mirror Phase 2.6 hardenings (commands/ultraexecute-local.md).
+# GH #47721). Mirror Phase 2.6 hardenings (commands/trekexecute.md).
 export GIT_OPTIONAL_LOCKS=0
 
 # Per-child guardrails (operator may override via env). Match Phase 2.6
@@ -99,7 +99,7 @@ if [ "${TREKEXECUTE_SKIP_PREFLIGHT:-0}" != "1" ]; then
   fi
 fi
 
-echo "=== Ultraplan Headless Execution (Worktree-Isolated) ==="
+echo "=== Voyage Headless Execution (Worktree-Isolated) ==="
 echo "Plan: {plan_path}"
 echo "Sessions: {total_sessions}"
 echo "Repo root: $REPO_ROOT"
@@ -138,7 +138,7 @@ cd "$REPO_ROOT"
 {# For each session in the wave: push BEFORE merge (Hard Rule 19 — push-before-cleanup). }
 git push origin "trek/{slug}/session-{n}" 2>/dev/null || true
 git merge --no-ff "trek/{slug}/session-{n}" \
-  -m "merge: ultraplan session {n} — {title}"
+  -m "merge: trekplan session {n} — {title}"
 if [ $? -ne 0 ]; then
   echo "MERGE CONFLICT: session {n}. Conflicting files:"
   git diff --name-only --diff-filter=U