End-to-end group orchestration (tracer bullet)

[hsubra89]

Resolves #78

Automated implementation by rlph.

[hsubra89]

Review Summary

Overall the implementation is solid — security review is clean and the core group orchestration logic is correct. Two warnings and a handful of style/info items.

Warnings

• src/orchestrator.rs L671 — run_group_iteration_start returns Err when no sub-issues are eligible in a brand-new group, but group state and worktree are already persisted at that point. On restart, run_group_iteration_resume handles the same scenario gracefully as Ok(NoEligibleTasks). This inconsistency means a group whose sub-issues are all externally blocked at creation time will crash the orchestrator once, then silently return NoEligibleTasks on every subsequent restart. Return Ok(NoEligibleTasks) in the start path too (or clean up group state on error).
• src/orchestrator.rs L456 — Awkward clone: standalone_tasks.iter().map(|t| (*t).clone()).collect::<Vec<_>>() → use standalone_tasks.to_vec() or .iter().cloned().collect().

Info

• src/sources/github.rs L219 — Simplify .map(|si| Self::parse_gql_sub(si)) → .map(Self::parse_gql_sub).
• src/sources/github.rs L109 — is_eligible and is_gql_eligible duplicate label-exclusion logic. Extract to a shared const EXCLUSION_LABELS.
• src/sources/github.rs L125 — parse_gql_issue and parse_gql_sub are near-identical. Consider a shared constructor or From impl.
• src/sources/github.rs L145 — fetch_eligible_task_groups_impl is pub but only used via the trait. Restrict to pub(crate) or use #[cfg(test)] visibility.
• src/sources/github.rs L181 — Unnecessary intermediate labeled_children collect — inline with child_ids.extend(...).
• src/sources/mod.rs L61 — all_sub_issue_ids for Standalone returns vec![task.id.clone()], which is misleading. Consider renaming to all_resolvable_ids or returning empty vec.
• src/sources/mod.rs L68 — is_complete unused outside tests. Consider #[cfg(test)] gating.
• src/state.rs L217 — Shadow bindings before the closure are unnecessary; construct inline.
• src/orchestrator.rs L836 — PR body construction: replace for-loop + vec + join with idiomatic iterator chain.
• src/orchestrator.rs L710 — run_group_iteration_resume re-fetches get_task_details for ALL sub-issues (including completed) each iteration. Only the next eligible sub-issue details are needed.
• src/orchestrator.rs L741 — Unnecessary borrow: &worktree_info creates &&WorktreeInfo; pass worktree_info directly.
• tests/orchestrator_integration.rs L2503 — No integration test covers the NoEligibleTasks flow when sub-issues are blocked by external deps.

[hsubra89]

The comment about "auto-select optimization removed" (L508) is inaccurate. Auto-select for single-candidate is present at L486: if groups.len() == 1 { ... }. The choose agent is only invoked when there are 2+ candidates.