Add agent task artifact loop primitives

[chubes4]

Summary

• Adds typed artifact output declarations and artifact-aware output bindings for agent-task plans while preserving existing {{outputs.*}} JSON Pointer bindings.
• Records artifact lineage on schedule aggregates so controller loops can route retries, review, and promotion from structured artifacts.
• Adds generic controller primitives for finding packet routing and validation-gated candidate patch promotion, including dedupe, lineage, pass/fail, and retry-limit states.

Fixes #3929.
Fixes #3930.
Fixes #3931.

Verification

• cargo fmt
• cargo test agent_task_scheduler::tests::
• cargo test agent_task_loop_controller::tests::
• cargo check

AI assistance

• AI assistance: Yes
• Tool(s): OpenCode (openai/gpt-5.5)
• Used for: Drafted the schema additions, scheduler/controller implementation, and targeted Rust tests; Chris remains responsible for review and validation.

[homeboy-ci]

Homeboy Results — homeboy

Lint

✅ lint — passed

ℹ️ Full options: homeboy docs commands/lint
ℹ️ Save lint baseline: homeboy lint homeboy --baseline
Deep dive: homeboy lint homeboy --changed-since 4795383

Artifacts and drill-down

• CI results artifact: homeboy-ci-results-homeboy-lint-quality-Linux contains immediate command JSON for this action invocation.
• Observation artifact: homeboy-observations-homeboy-lint-quality-Linux contains exported Homeboy run history for deeper queries.
• Drill-down: download the observation artifact, then run homeboy runs import <dir>, homeboy runs list, and homeboy runs findings <run-id>.
• Artifacts are attached to the workflow run: https://github.com/Extra-Chill/homeboy/actions/runs/27275333792

Audit

✅ audit — passed

• core_boundary_leak:core-agnostic-source — 2 finding(s)
• field_patterns — 2 finding(s)
• structural — 2 finding(s)
• Runs (Tests) — 1 finding(s)
• intra-method-duplication — 1 finding(s)
• Total: 8 finding(s)

Deep dive: homeboy audit homeboy --changed-since 4795383

Artifacts and drill-down

• CI results artifact: homeboy-ci-results-homeboy-audit-quality-Linux contains immediate command JSON for this action invocation.
• Observation artifact: homeboy-observations-homeboy-audit-quality-Linux contains exported Homeboy run history for deeper queries.
• Drill-down: download the observation artifact, then run homeboy runs import <dir>, homeboy runs list, and homeboy runs findings <run-id>.
• Artifacts are attached to the workflow run: https://github.com/Extra-Chill/homeboy/actions/runs/27275333792

Tooling versions

• Homeboy CLI: homeboy 0.227.9+fd9b6b40
• Extension: rust from https://github.com/Extra-Chill/homeboy-extensions
• Extension revision: 3b585be1
• Action: unknown@unknown