chore: remove dead openspec archive and stale references

The OpenSpec workflow was retired in 1.3.0 but the archive tree and
template/README references lingered, contradicting the closure-mode
contract. Drop the dead archive, fix the dangling pointers, and align
the docs homepages with the single authoritative AI guidance file
(CLAUDE.md). Also remove a redundant .gitkeep now that the directory
ships real headers.

Generated with [Devin](https://devin.ai)

Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>

Author: LessUp

.github/ISSUE_TEMPLATE/feature_request.yml

@@ -28,9 +28,3 @@ body:
     attributes:
       label: Alternatives
       description: Any alternative solutions you've considered
-
-  - type: textarea
-    id: openspec
-    attributes:
-      label: OpenSpec notes
-      description: If you already know the affected capability or a proposed change id, note it here.

.github/PULL_REQUEST_TEMPLATE.md

@@ -4,12 +4,6 @@
 
 Brief description of what this PR adds or fixes.
 
-## OpenSpec
-
-- [ ] This change is trivial and does not need an OpenSpec change
-- [ ] I updated or created the relevant OpenSpec change under `openspec/changes/`
-- [ ] I reviewed the affected capability specs under `openspec/specs/`
-
 ## Type of Change
 
 - [ ] Bug fix (non-breaking change which fixes an issue)

CHANGELOG.md

@@ -2,6 +2,14 @@
 
 All notable changes to this project will be documented in this file.
 
+## [Unreleased]
+
+### Removed
+- Dead `openspec/` archive tree (26 files). The OpenSpec workflow was already retired in 1.3.0; the lingering archive directory contradicted that decision and carried no active specs.
+- Stale OpenSpec references from the pull request template, feature request issue template, and README contributor pointers.
+- Dangling `AGENTS.md` reference on the bilingual docs homepages; `CLAUDE.md` is the only authoritative AI guidance file.
+- Redundant `examples/03-modern-cpp/include/.gitkeep` (the directory now ships five real headers).
+
 ## [1.3.0] - 2025-05
 
 ### Added

README.md

@@ -99,4 +99,4 @@ cmake --preset=ubsan && cmake --build build/ubsan && ctest --preset=ubsan
 
 ## Contributing
 
-See `CONTRIBUTING.md` for the contributor workflow, hooks setup, and OpenSpec process.
+See `CONTRIBUTING.md` for the contributor workflow and hooks setup.

README.zh-CN.md

@@ -100,4 +100,4 @@ cmake --preset=ubsan && cmake --build build/ubsan && ctest --preset=ubsan
 
 ## 贡献
 
-贡献流程、hooks 配置与 OpenSpec 约定见 `CONTRIBUTING.zh.md`。
+贡献流程与 hooks 配置见 `CONTRIBUTING.zh.md`。

docs/en/index.md

@@ -170,7 +170,7 @@ Use the preset-driven path first. It is the shortest route that still preserves
 ## Expert reader callouts
 
 - **Interviewer or reviewer:** start with [Architecture](/en/architecture/) and [Research](/en/research/). Those pages expose the validation model and external context fastest.
-- **Future maintainer:** read [Module Atlas](/en/academy/module-atlas), [Repository Topology](/en/architecture/repository-topology), and the repository-level guidance in `AGENTS.md` and `CLAUDE.md` on GitHub.
+- **Future maintainer:** read [Module Atlas](/en/academy/module-atlas), [Repository Topology](/en/architecture/repository-topology), and the repository-level guidance in `CLAUDE.md` on GitHub.
 - **Practicing engineer:** use the [Playbook](/en/playbook/) for commands, then move to profiling and sanitizer routes only after a baseline run succeeds.
 
 ## Operational routes

docs/zh/index.md

@@ -170,7 +170,7 @@ layout: home
 ## 面向熟练读者的提示
 
 - **面试官或评审者：** 先读[架构](/zh/architecture/)和[研究](/zh/research/)。这两部分最快暴露验证模型与外部上下文。
-- **未来维护者：** 阅读[模块总览](/zh/academy/module-atlas)、[仓库拓扑](/zh/architecture/repository-topology)，以及 GitHub 上的 `AGENTS.md` 与 `CLAUDE.md`。
+- **未来维护者：** 阅读[模块总览](/zh/academy/module-atlas)、[仓库拓扑](/zh/architecture/repository-topology)，以及 GitHub 上的 `CLAUDE.md`。
 - **实践工程师：** 先用[实践手册](/zh/playbook/)获取命令，再在基线通过后进入 profiling 与 sanitizer 路线。
 
 ## 操作路线