Merge upstream origin/main (v2.60.0) with fork customizations preserved

Incorporates 78 upstream commits while preserving all local fork intent:
- Keep deleted: dhh-rails, kieran-rails, dspy-ruby, andrew-kane-gem-writer (FastAPI pivot)
- Merge both: ce-review (zip-agent-validator + design-conformance-reviewer wiring),
  kieran-python-reviewer (upstream pipeline + FastAPI conventions),
  ce-brainstorm/ce-plan/ce-work (upstream improvements + deploy wiring checks),
  todo-create (upstream template refs + assessment block),
  best-practices-researcher (upstream rename + FastAPI refs)
- Accept remote: 142 remote-only files, plugin.json, README.md
- Keep local: 71 local-only files (custom agents, skills, commands, voice)

Co-Authored-By: Claude Opus 4.6 (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)