docs(config): orchestration timeout fields missing from default.toml

[bug-ops]

Description

PR #3860 added three new OrchestrationConfig fields — aggregator_timeout_secs, planner_timeout_secs, and verifier_timeout_secs — with Serde defaults, but none of them appear as commented entries in crates/zeph-config/config/default.toml.

Per the project documentation rule, every config key must be documented in default.toml (commented out when optional). Operators upgrading from an older config file have no reference entry to copy-paste and adjust.

Reproduction Steps

1. Open crates/zeph-config/config/default.toml.
2. Search for aggregator_timeout_secs — not found.
3. Compare against other orchestration fields (e.g. task_timeout_secs, aggregator_max_tokens) that are present and commented.

Expected Behavior

The [orchestration] section in default.toml should include:

# Timeout in seconds for aggregation LLM calls (0 rejected by validation). Default: 60.
# aggregator_timeout_secs = 60

# Timeout in seconds for planner LLM calls (0 rejected by validation). Default: 120.
# planner_timeout_secs = 120

# Timeout in seconds for verifier LLM calls (0 rejected by validation). Default: 30.
# verifier_timeout_secs = 30

Actual Behavior

The three fields are absent from default.toml; only the Serde default functions provide the values.

Environment

• Version: b668009
• Features: full

Logs / Evidence

grep -n 'aggregator_timeout_secs\|planner_timeout_secs\|verifier_timeout_secs' crates/zeph-config/config/default.toml returns empty.