Merge step (b): carry in local-only files at original paths

Brings 47 local-only files from backup-local-main into the merge-upstream
branch at their pre-rename paths. Subsequent steps will rename these to
the ce-* convention and port shared-file merges.

Includes:
- Custom skills: john-voice, jira-ticket-writer, hugo-blog-publisher,
  weekly-shipped, proof-push, ship-it, story-lens, sync-confluence,
  excalidraw-png-export, python-package-writer, fastapi-style,
  upstream-merge
- Custom agents: design-conformance-reviewer, tiangolo-fastapi-reviewer,
  zip-agent-validator, python-package-readme-writer, lint
- Custom commands: essay-edit, essay-outline, pr-comments-to-todos,
  resolve_todo_parallel, workflows/{plan,review,work}
- Local mods to ce-review/SKILL.md + review-output-template.md (will be
  ported to ce-code-review in a later step)

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

plugins/compound-engineering/skills/upstream-merge/assets/merge-triage-template.md

@@ -0,0 +1,57 @@
+---
+status: pending
+priority: p2
+issue_id: "XXX"
+tags: [upstream-merge]
+dependencies: []
+---
+
+# Merge Conflict: [filename]
+
+## File Info
+
+| Field | Value |
+|-------|-------|
+| **File** | `path/to/file` |
+| **Category** | agent / command / skill / config / other |
+| **Conflict Type** | content / modify-delete / add-add |
+
+## What Changed
+
+### Remote Version
+
+[What the upstream version added, changed, or intended]
+
+### Local Version
+
+[What the local version added, changed, or intended]
+
+## Diff
+
+<details>
+<summary>Show diff</summary>
+
+```diff
+[Relevant diff content]
+```
+
+</details>
+
+## Recommendation
+
+**Suggested resolution:** Accept remote / Keep local / Merge both / Keep deleted
+
+[Reasoning for the recommendation, considering the local fork's guiding principles]
+
+## Decision
+
+**Resolution:** *(filled during triage)*
+
+**Details:** *(specific merge instructions if "merge both")*
+
+## Acceptance Criteria
+
+- [ ] Resolution applied correctly
+- [ ] No content lost unintentionally
+- [ ] Local intent preserved
+- [ ] File validates (JSON/YAML if applicable)