docs: add GPT-5.3 OpenCode delivery playbook

README.md

@@ -100,6 +100,10 @@ See `docs/roadmap.md`.
 
 See `docs/workflows-playbook.md` for usage patterns.
 
+## AI Delivery Playbook
+
+Use `docs/gpt53-opencode-playbook.md` as the default runbook for GPT-5.3 + OpenCode execution to reduce rework.
+
 ## Open Source Readiness
 
 - community templates in `.github/`

docs/gpt53-opencode-playbook.md

@@ -0,0 +1,49 @@
+# GPT-5.3 + OpenCode Delivery Playbook
+
+Use this one-page runbook to reduce rework when building with GPT-5.3 and OpenCode.
+
+## Principles
+
+- plan before code, verify before PR
+- follow existing repo patterns before introducing new ones
+- make decisions explicit when they affect prompts, model behavior, or workflow
+- leave a clean handoff artifact at session end
+
+## Default Flow
+
+1. Frame scope and definition of done.
+2. Inspect existing patterns and constraints.
+3. Implement in small, testable slices.
+4. Verify with stack-specific checks.
+5. Prepare PR with full context from branch divergence.
+6. Capture session handoff for continuity.
+
+## Trigger -> Skill -> Expected Output
+
+| Trigger | Skill(s) | Expected Output |
+|---|---|---|
+| new task request with ambiguity | `Prompt Wizard`, `workflow` | clear task statement with in-scope/out-of-scope and verification checklist |
+| editing unfamiliar code | `code-search`, `Pattern Analysis` | file map, current conventions, and safe insertion points |
+| implementing code changes | `language-conventions`, `workflow` | minimal-diff changes aligned to existing standards |
+| adding or changing tests | `Testing Strategy` | test pyramid plan and targeted coverage additions |
+| prompt/model behavior design | `Prompt Engineering` | versioned prompt contract (role, constraints, schema, examples) |
+| preventing AI regressions | `AI Evaluation` | golden dataset, scoring rubric, and regression thresholds |
+| architecture-impacting choice | `ADR Template` | ADR with options, rationale, consequences, and review triggers |
+| git state unclear | `git-status`, `git-workflows` | staged/unstaged snapshot, branch state, and next safe git step |
+| ready to publish work | `github-workflow` | PR with why, testing notes, blockers, and CI status summary |
+| session ending or context switch | `handover` | concise continuity note with decisions, risks, and ordered next steps |
+
+## GPT-5.3 Guardrails
+
+- require structured outputs for machine-consumed steps (JSON schema or strict markdown template)
+- keep prompt versions in repo and tie changes to eval results
+- treat prompt updates like code changes: diff, review, validate, and document
+- fail builds when core eval thresholds regress
+
+## PR Ready Checklist
+
+- [ ] scope is explicit (in/out) and unchanged during implementation
+- [ ] change matches local conventions and avoids unrelated refactors
+- [ ] required checks/tests executed (or risks documented if blocked)
+- [ ] PR explains why, not only what
+- [ ] handoff note exists when work is incomplete or multi-session