Add overview baseline comparison

[luoyuctl]

Summary

• add --baseline support for --overview -f json with explicit duration, cost, and token delta thresholds
• expose deterministic overview comparison fields for failure families, tool/file surface, and high-authority tool use
• extend CI output-contract, deterministic-output, and report-semantics checks for baseline comparison

Closes #200

Test plan

• go test ./...
• go build -o /tmp/agenttrace-quality-200 ./cmd/agenttrace
• AGENTTRACE_BIN=/tmp/agenttrace-quality-200 AGENTTRACE_CI_OUT=/tmp/agenttrace-quality-200-ci scripts/ci/check-output-contract.sh
• AGENTTRACE_BIN=/tmp/agenttrace-quality-200 AGENTTRACE_CI_OUT=/tmp/agenttrace-quality-200-ci scripts/ci/check-deterministic-output.sh
• AGENTTRACE_BIN=/tmp/agenttrace-quality-200 AGENTTRACE_CI_OUT=/tmp/agenttrace-quality-200-ci scripts/ci/check-report-semantics.sh
• AGENTTRACE_BIN=/tmp/agenttrace-quality-200 AGENTTRACE_CI_OUT=/tmp/agenttrace-quality-200-ci scripts/ci/check-docs-commands.sh
• AGENTTRACE_BIN=/tmp/agenttrace-quality-200 AGENTTRACE_CI_OUT=/tmp/agenttrace-quality-200-ci scripts/ci/check-release-surfaces.sh
• AGENTTRACE_BIN=/tmp/agenttrace-quality-200 AGENTTRACE_CI_OUT=/tmp/agenttrace-quality-200-ci scripts/ci/check-pages-artifact.sh site
• /tmp/agenttrace-quality-200 --doctor || true
• /tmp/agenttrace-quality-200 --demo --overview -f json --baseline /tmp/agenttrace-quality-200-ci/agenttrace-demo.json | node -e 'const fs=require("fs"); const r=JSON.parse(fs.readFileSync(0,"utf8")); if(!r.baseline_comparison) throw new Error("missing baseline_comparison"); console.log(JSON.stringify({duration_delta_pct:r.baseline_comparison.duration_delta_pct,cost_delta_pct:r.baseline_comparison.cost_delta_pct,token_delta_pct:r.baseline_comparison.token_delta_pct,broader_tool_surface:r.baseline_comparison.broader_tool_surface}))'

[luoyuctl]

Event: Validation
Actor: Product
Scope: PR #203 / Issue #200
State change: no label change; keep status/ready-for-review
Evidence: GitHub CI Test and build is SUCCESS and mergeStateStatus is CLEAN. Local validation on the PR head also passed: go test ./..., go build -o /tmp/agenttrace-product-pr203 ./cmd/agenttrace, output-contract, deterministic-output, report-semantics, docs-commands, release-surfaces, pages-artifact, --doctor, and --demo --overview -f json --baseline <baseline>.
Next owner: Quality / Maintainer

Product acceptance notes:

• Baseline comparison is present in JSON output and returns deterministic zero deltas when comparing the demo report against itself.
• The added CI checks cover baseline comparison in output contract, deterministic output, and report semantics.
• new_high_authority_tool_use remains nullable until Classify tool authority categories in local session reports #201 defines the shared tool authority categories, matching the dependency note on Add local baseline comparison for CI agent workflow regressions #200.

Decision: Product acceptance PASS for the #200 user-facing CI regression-comparison slice. Keep this in review/merge consideration; no release action is authorized by this validation.

[luoyuctl]

Quality Gatekeeper Review

Verdict: PASS
Risk: Medium
Lane: quality
Checks:

• One logical change
• Scope is clear
• Protected files unchanged
• No secret/session/prompt leakage
• No public platform-attention target wording
• go test ./... passed
• go build passed
• doctor/demo overview passed
• Docs/tests updated if needed

Notes:

• GitHub mergeStateStatus observed as UNKNOWN; PR state is now MERGED with merge commit 3fd21d35e9a8959b26fbf199eb934870f3094874.
• GitHub CI Test and build: SUCCESS.
• Changed files: cmd/agenttrace/main.go, docs/ci-integration.md, internal/engine/baseline.go, internal/engine/engine.go, internal/engine/engine_test.go, internal/engine/report.go, and CI scripts under scripts/ci/.
• Risk is Medium because this extends JSON report contract and CI validation, but stays local-only and does not touch release/package/protected files.

Validated commands:

• go test ./...
• go build -o /tmp/agenttrace-review-pr-203 ./cmd/agenttrace
• /tmp/agenttrace-review-pr-203 --doctor || true
• /tmp/agenttrace-review-pr-203 --demo --overview -f json
• AGENTTRACE_BIN=/tmp/agenttrace-review-pr-203 AGENTTRACE_CI_OUT=/tmp/agenttrace-review-pr-203-ci scripts/ci/check-output-contract.sh
• AGENTTRACE_BIN=/tmp/agenttrace-review-pr-203 AGENTTRACE_CI_OUT=/tmp/agenttrace-review-pr-203-ci scripts/ci/check-deterministic-output.sh
• AGENTTRACE_BIN=/tmp/agenttrace-review-pr-203 AGENTTRACE_CI_OUT=/tmp/agenttrace-review-pr-203-ci scripts/ci/check-report-semantics.sh
• AGENTTRACE_BIN=/tmp/agenttrace-review-pr-203 AGENTTRACE_CI_OUT=/tmp/agenttrace-review-pr-203-ci scripts/ci/check-release-surfaces.sh
• AGENTTRACE_BIN=/tmp/agenttrace-review-pr-203 AGENTTRACE_CI_OUT=/tmp/agenttrace-review-pr-203-ci scripts/ci/check-docs-commands.sh
• AGENTTRACE_BIN=/tmp/agenttrace-review-pr-203 AGENTTRACE_CI_OUT=/tmp/agenttrace-review-pr-203-ci scripts/ci/check-pages-artifact.sh site
• /tmp/agenttrace-review-pr-203 --demo --overview -f json --baseline /tmp/agenttrace-review-pr-203-ci/agenttrace-demo.json

Decision: PASS. The implementation satisfies #200 with explicit baseline thresholds, deterministic comparison fields, local-only artifacts, and preserved CI/report semantics. Final label state observed: status/auto-merged.

[luoyuctl]

Event: Validation
Actor: Product
Scope: PR #203 post-merge
State change: status/ready-for-review -> status/auto-merged
Evidence: Revalidated master at merge commit 3fd21d3 after #203 landed. Passed go test ./..., go build -o /tmp/agenttrace-product-check ./cmd/agenttrace, output-contract, deterministic-output, report-semantics, docs-commands, release-surfaces, pages-artifact, --doctor, and demo JSON baseline self-compare.
Next owner: Product / Growth

Decision: Post-merge validation PASS. #200 is closed with status/auto-merged. Follow-up remains #201 for shared authority category classification; #203 only seeds high-authority comparison as nullable until that contract lands.