feat: 品牌替换 + 启动优化 + AGENTS.md 模板定制

- 品牌替换：OpenCode/opencode → AirCoding/aircoding（16+ 文件）
- Logo ASCII art：修复 left/right 行数不匹配导致的启动崩溃
- 启动诊断：添加 OPENCODE_PRINT_TIMING 计时探针
- dev 模式默认 --pure 跳过外部插件加载
- AGENTS.md 模板：追加 AirCoding 多 Agent 专项段落
- architect prompt + plugin：强化 AGENTS.md 产出验证

.github/ISSUE_TEMPLATE/bug-report.yml

@@ -0,0 +1,66 @@
+name: Bug report
+description: Report an issue that should be fixed (avoid pasting giant AI generated summaries or your issue may be closed/ignored)
+body:
+  - type: textarea
+    id: description
+    attributes:
+      label: Description
+      description: Describe the bug you encountered
+      placeholder: What happened?
+    validations:
+      required: true
+
+  - type: input
+    id: plugins
+    attributes:
+      label: Plugins
+      description: What plugins are you using?
+    validations:
+      required: false
+
+  - type: input
+    id: opencode-version
+    attributes:
+      label: OpenCode version
+      description: What version of OpenCode are you using?
+    validations:
+      required: false
+
+  - type: textarea
+    id: reproduce
+    attributes:
+      label: Steps to reproduce
+      description: How can we reproduce this issue?
+      placeholder: |
+        1.
+        2.
+        3.
+    validations:
+      required: false
+
+  - type: textarea
+    id: screenshot-or-link
+    attributes:
+      label: Screenshot and/or share link
+      description: Run `/share` to get a share link, or attach a screenshot
+      placeholder: Paste link or drag and drop screenshot here
+    validations:
+      required: false
+
+  - type: input
+    id: os
+    attributes:
+      label: Operating System
+      description: what OS are you using?
+      placeholder: e.g., macOS 26.0.1, Ubuntu 22.04, Windows 11
+    validations:
+      required: false
+
+  - type: input
+    id: terminal
+    attributes:
+      label: Terminal
+      description: what terminal are you using?
+      placeholder: e.g., iTerm2, Ghostty, Alacritty, Windows Terminal
+    validations:
+      required: false