[1.2.0] - 2026年04月21日

Within-stage crash-resume. A pipeline killed mid-Stage-N no longer loses
that stage's partial progress — the rerun skips any artifact whose
input hash still matches the checkpoint. Budget-cap halts are now
graceful exits with a resume-message format.

Added

• Within-stage checkpointing. Stages 2 (file summaries), 3 (class
  docs), 4 (package rollups), 5 (mermaid), and 6 (tech-debt topics) now
  write to state.artifact_index after every completed artifact, under
  an asyncio.Lock. Mid-stage crash + rerun never re-calls the LLM for
  already-produced artifacts.
• Atomic artifact writes. New designdoc.io_utils.atomic_write(path, content) writes to a sibling .tmp then os.replace() (POSIX-atomic).
  Every artifact and the .designdoc-state.json file itself use it.
• Graceful budget halt. BudgetExceededError mid-stage now sets
  state.halted_on_budget=True, marks the stage FAILED, saves state, and
  the CLI prints budget exhausted at $X / cap $Y. Run designdoc resume --budget <new-cap> to continue with exit 0.
• Observability. Orchestrator stage-start log lines include the
  count of already-checkpointed artifacts (e.g., [3/9] stage class_docs: 40 artifacts checkpointed).

Changed

• PipelineState.artifact_index is now dict[str, dict[str, str]]
  (was dict[str, str]) carrying {"path": ..., "input_hash": ...}
  per artifact. Old-shape state files are migrated in-memory on load
  with empty input_hash — safe fallback that forces reprocessing.
• Orchestrator.run() no longer re-raises BudgetExceededError. The
  CLI reads state.halted_on_budget after the run and formats the
  resume message itself. Exit code 0 (resumable), not 4 (crash).

Fixed

• Concurrent state.save() under asyncio.gather is now serialized by
  a module-level asyncio.Lock, preventing lost writes when
  parallelism > 1.

Incremental regeneration, parallel execution, and UX polish.

Measured results

Measured on `tests/fixtures/tiny_repo`:

The 37% cold speedup comes from `parallelism=3` actually running three LLM calls concurrently per stage in the per-file / per-class / per-package loops. The warm-run drop is incremental regeneration refusing to redo work when inputs are unchanged.

Added

• Incremental regeneration. Every generated artifact records the SHA1 of its inputs in `.designdoc-state.json`. Subsequent runs skip unchanged work:
  • Stage 2/3 skip files whose source hash matches the previous run.
  • Stage 4/5/7 skip rollups whose input-class-doc hashes are unchanged.
  • Stage 6 uses a tech-debt manifest hash to skip cross-ref research.
• Parallel per-artifact execution. Stages 2, 3, 4, and 6 now run their per-file / per-class / per-package / per-topic loops under an `asyncio.Semaphore(parallelism)` gate. Default parallelism is 3.
• `--parallelism N` CLI flag on `designdoc generate` and `designdoc resume` (overrides `config.parallelism`).
• Progress logging. Orchestrator emits `[N/9] stage x starting` and `[N/9] stage x done in Xs` lines so long runs are observable.
• `designdoc status` cache-readiness hints. Reports `prev_hashes` and `rollup_hashes` counts so users can see what will skip on the next run.
• Incremental-regeneration benchmark (`tests/e2e/test_incremental_bench.py`) — real-API cold/warm run against `tiny_repo`; gated on `claude` CLI login.

Changed

• README documents measured parallel speedup and incremental behavior.
• Config fields `include_languages`, `output_dir`, and `diagram_format` are now wired through to the pipeline (previously declared but unused).
• CI workflow runs on `feat/`, `fix/`, `bench/`, `chore/`, `docs/`, and `test/` branches.

Fixed

• `--config` path and MCP server list are now passed through to every stage.
• Mermaid double-append bug in the Stage 5 rollup path.
• CI `mmdc` invocation now runs with `--no-sandbox` so Puppeteer works on GitHub Actions runners.
• Three ultrareview findings on option passthrough.

Docs

• Authentication uses the local `claude` CLI (Pro/Max subscription) as SDK transport. No `ANTHROPIC_API_KEY` required for normal use.

Full changelog: v1.0.0...v1.1.0 · CHANGELOG.md

First feature-complete release. Implements the 9-stage harness-engineered documentation pipeline described in plans/2026_04_16_designdoc_gen_v1.md.

Retroactive tag — the release was never formally tagged at the time. See CHANGELOG.md for full details.

Core harness (the invariants)

• 3-attempt doer/checker loop (MAX_ATTEMPTS = 3, the canonical retry cap). A constitutional guard test prevents the constant from ever being exposed as user config.
• Checker isolation. The doer's scratchpad never reaches the checker — the checker sees source + doer final output + its own system prompt, nothing else.
• Schema-validated verdicts. Malformed JSON produces a synthetic fail verdict; never silent success.
• Budget cap. CostAccumulator raises BudgetExceededError when exceeded; persisted to state so resumed runs honor the remaining budget.
• Resumable state. Each completed stage writes a checkpoint to <output>/.designdoc-state.json; a crashed run resumes from the last completed stage.
• HIL fallback. Unresolved disputes ship with inline <!-- HIL: HIL-XXX --> comments + YAML ledger rather than blocking the pipeline.

Nine pipeline stages

• Stage 0 — Language discovery + file tree (no LLM).
• Stage 1 — AST-lite signatures (Python `ast`; TS/JS regex fallback).
• Stage 2 — Per-file summary (LLM doer + Pydantic schema checker).
• Stage 3 — Class docs (LLM doer + LLM quality checker — first LLM-on-LLM stage).
• Stage 4 — Package README rollups.
• Stage 5 — Mermaid diagrams via two-checker loop: deterministic `mmdc` syntax check plus an LLM semantic check. Both must pass.
• Stage 6 — Tech-debt researcher with Perplexity / Context7 MCP cross-ref.
• Stage 7 — `SYSTEM_DESIGN.md` + `ARCHITECTURE.md` rollup.
• Stage 8 — Finalize: README TOC + `hil-issues.yaml` emit.

CLI and plugin

• Typer CLI: `generate`, `resume`, `status`, `resolve`.
• `/designdoc` Claude Code slash command.
• HIL walker CLI helpers.