Re-enable cosmetic yamllint rules after normalizing vendored manifests

To get CI green on the initial publish, `.yamllint` disables several cosmetic rules (`indentation`, `colons`, `braces`, `document-start`, `line-length`) that the vendored upstream manifests do not follow. Structural checks (syntax, duplicate keys, empty values, trailing whitespace) remain enabled.

**Action (optional, quality)**: progressively normalize the vendored YAML (consistent indentation, `---` document starts, brace/colon spacing) and re-enable the corresponding rules. `line-length` should stay disabled because some manifests embed machine-generated Grafana dashboard JSON on single long lines.

Context: see the CI setup in `.github/workflows/ci.yml` and `.yamllint`.

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Generated by Coder Agents, on behalf of @ausbru87.

从 .yamllint 和 .github/workflows/ci.yml 开始，然后检查当前违反外观规则的 vendored YAML 清单。在可行的情况下规范缩进、文档起始位置以及大括号和冒号周围的空格，重新启用这些规则，继续对生成的 dashboard JSON 禁用 line-length，并确认 CI 仍然通过。

由索引模型根据 Issue 内容生成。