Sync iteration-025 latency fast paths (small-gate review skip, proportional review-lite, lead slim)

[jcarlosrodicio]

Summary

Ports iteration-025 harness latency fast paths into the public kit:

• Small-gate fast path: a declared small change of at most two files may skip final review when it does not touch protected surfaces, is not destructive, and does not require new tests. lead records review_skipped_reason (small_gate_pass | protected_surface | destructive_diff | tests_required | scope_not_small | human_decision).
• Proportional review-lite: reviewer depth is skipped / trivial / lite / full (see commands.md /review-preflight). Lite consumes the developer Verification Envelope and must not re-run green suites; medium/large and sensitive surfaces keep an intact final verdict.
• Condensed small card: six fields (objective, success, validation, diff base, constraints, output) replace the full Task Contract / handoff_packet / Result+Verification stack when the unique small-gate in opencode/docs/ai/harness/agents.md holds.
• Lead slim + on-demand playbooks: fast-router over phases, on-demand Skill Resolution, AHE details in opencode/docs/ai/harness/playbooks/lead-ahe-flow.md.
• Phase-0 telemetry v2: execution trees expose request-turn ids, paired handoff timestamps, review_skipped_reason, and post-hoc diff_size.
• Red routing fixtures: synthetic failing corpus (Save-changes button / Rubik canvas prompts, generic ids) locked so the classic corpus stays green.

Validation

• Private: node scripts/check-harness.mjs passed; git diff --check passed.
• Public: ./scripts/check.sh passed (harness + public boundary).
• Public: node --test opencode/scripts/collect-session-evidence.test.mjs 17/17.
• Public: node --test opencode/scripts/replay-routing.test.mjs 69/69 (including red lock).
• Public: git diff --check passed.
• Leak check on working tree, staged diff, and new files: no private markers.

Boundary

no private config, no local MCP wiring, no credentials, no provider URLs (incl. nan), no raw transcripts, no machine-local paths.