feature: Agent 2.0 配置模板、配置环境变量管理 (closed #1681)

[wyyalt]

PR

CheckList（PR Assigners）

确认已完成以下操作：

• 已将分支与当前合入分支同步
• 已在关联 Issue 中补充「功能自测」部分内容
• 已更新关联 Issue 的状态 backlog -> todo -> for test -> tested（需通过测试同学测试） -> done
• 将 PR 添加上 pr/reviewable

CheckList（PR Reviewers）

确认已完成以下操作：

• 检查关联 Issue 「功能自测」部分内容
• 必要时打回 pr/reviewable，要求重新修改
• 及时 Approve

[codecov-commenter]

Codecov Report

Merging #1754 (b7ed25c) into v2.4.1-dev (e8dbe68) will increase coverage by 0.06%.
The diff coverage is 87.44%.

@@              Coverage Diff               @@
##           v2.4.1-dev    #1754      +/-   ##
==============================================
+ Coverage       73.87%   73.93%   +0.06%     
==============================================
  Files             393      396       +3     
  Lines           26480    26706     +226     
==============================================
+ Hits            19562    19745     +183     
- Misses           6918     6961      +43     

Files Changed	Coverage Δ
apps/core/tag/targets/base.py	88.23% <73.33%> (-1.54%)	⬇️
...ckend/subscription/steps/agent_adapter/handlers.py	78.78% <78.78%> (ø)
apps/backend/agent/config_parser.py	79.31% <79.31%> (ø)
apps/node_man/models.py	76.81% <82.75%> (+0.14%)	⬆️
apps/core/tag/targets/agent.py	92.30% <92.30%> (ø)
apps/backend/agent/artifact_builder/base.py	93.80% <98.11%> (+1.62%)	⬆️
apps/backend/agent/artifact_builder/agent.py	100.00% <100.00%> (ø)
apps/backend/agent/artifact_builder/proxy.py	89.28% <100.00%> (+0.39%)	⬆️
apps/backend/exceptions.py	100.00% <100.00%> (ø)
apps/backend/management/commands/init_agents.py	92.68% <100.00%> (+0.18%)	⬆️
... and 5 more

... and 4 files with indirect coverage changes