docs(delegate): document max_concurrent_children and max_spawn_depth …

[MorAlekss]

Summary

Documents two existing but undocumented delegate_task configuration parameters: max_concurrent_children and max_spawn_depth. Both are already implemented in code but easy to miss without reading the source.

What changed

• cli-config.yaml.example: uncommented and expanded descriptions for max_concurrent_children and max_spawn_depth
• tools/delegate_tool.py:
  • _get_max_concurrent_children(): added warning log when value > 10
  • tool description string: added paragraph linking to delegation.* config keys and nested delegation requirements
• website/docs/guides/delegation-patterns.md: added "Tuning Concurrency and Depth" table to the Constraints section

Why

Skills like #379 (simplify, 3 parallel reviewers) and custom batch workflows need users to know that (a) the concurrency limit is configurable and (b) nested delegation requires both role="orchestrator" and max_spawn_depth >= 2. Currently neither is discoverable without reading delegate_tool.py source.

Example configuration

delegation:
  max_concurrent_children: 10   # default 3; floor 1, no hard ceiling
  max_spawn_depth: 2            # default 1; clamped [1, 3]

Raising max_spawn_depth to 2+ enables role="orchestrator" children to spawn their own workers.

Testing

No functional code changes - docs and logging only. Verified that cli-config.yaml.example parses as valid YAML.

[alt-glitch]

Likely duplicate of #13745 (merged) — same delegation config keys (max_concurrent_children, max_spawn_depth) already documented there. Please verify this PR adds content beyond what #13745 covered.

[MorAlekss]

@alt-glitch Not a duplicate. #13745 covered configuration.md, environment-variables.md, and features/delegation.md. This PR covers different files: cli-config.yaml.example (uncommented and expanded the config knobs), tools/delegate_tool.py (cost warning log + schema description update), and guides/delegation-patterns.md (concurrency/depth table). Complementary, not overlapping.

[teknium1]

Merged via #15454 (rebase-merge) with your authorship preserved on the doc commit. The only tweak: kept the two knobs commented in cli-config.yaml.example so users aren't pinned to the literal default when we raise it later. Improved comments, warning, docs table, and tool-description update all landed as-is. Thanks for the thorough documentation pass — these two knobs were genuinely underdocumented.