Add librarian Stage 2 v1: promote dispatcher

scripts/librarian_promote.py is the first Stage 2 piece: a
vendor-agnostic LLM dispatcher that drafts a docs/research/ note
from a given docs/archive/ entry. It assembles the prompt by
stitching scripts/librarian-prompt.md (system) onto the archive
body with a "draft a research note per the rules above" task
instruction, then shells out to the CLI selected by LIBRARIAN_LLM
({claude|codex|gemini}; default claude). The LLM's stdout is
captured to runs/tmp/librarian-promote-<timestamp>-draft.md for
human review — the script never writes into docs/research/ itself.

Refusal cases:
- path not under docs/archive/
- target docs/research/<stem>.md already exists (after stripping any
  -YYYY-MM-DD suffix)
- archive missing

If the LLM judges the archive non-promotable, it is instructed to
return a single SKIP: <reason> line instead of fabricating a draft.

--show-prompt prints the assembled prompt without invoking the LLM,
useful for inspecting what would be sent.

Plan updated: Stage 2 v1 marked complete; remaining Stage 2 work
(MEMORY drift fixup, duplicate-merge, survey mode) catalogued.
Next concrete step is a smoke test against one real archive entry.

Adds one ignore-list entry for docs/research/option-a-bench-result.md
which appears in the plan as a hypothetical accept target.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

docs/plans/librarian.md

@@ -183,11 +183,40 @@ routing the dated experiments and design analysis out of the file:
 extracts via a "See Also" section. AGENTS.md soft-cap rule reworded
 to clarify it is a *routing trigger*, not a split mandate.
 
+## Stage 2 v1: promote dispatcher
+
+✅ `scripts/librarian_promote.py`. Takes a `docs/archive/*.md` path,
+stitches `scripts/librarian-prompt.md` (system prompt) onto the
+archive body with a "draft a research note" task instruction, then
+shells out to the LLM CLI selected by `LIBRARIAN_LLM`
+(claude / codex / gemini; default claude). Output is captured to
+`runs/tmp/librarian-promote-<timestamp>-draft.md` for human review;
+the script never writes into `docs/research/` itself. `--show-prompt`
+prints the assembled prompt for inspection without calling the LLM.
+
+Refuses to run if:
+- the path is not under `docs/archive/`,
+- the implied target `docs/research/<stem>.md` already exists, or
+- the file is missing.
+
+If the LLM judges the archive non-promotable, it is instructed to
+return a single line `SKIP: <reason>` instead of a draft.
+
+## Stage 2 remaining
+
+- MEMORY.md drift fixup mode (read drift report, propose one-line
+  diffs).
+- Duplicate-doc merge proposal mode.
+- Survey mode: scan all archive entries lacking a research
+  counterpart and run `librarian_promote` on each, accumulating
+  drafts under one timestamped directory.
+
 ## Next Concrete Step
 
-Stage 2 — LLM judgment dispatcher. Read `librarian-<timestamp>.json`
-+ relevant doc bodies, route to `LIBRARIAN_LLM={claude|codex|gemini}`
-with `scripts/librarian-prompt.md` as system prompt, emit a unified
-diff under `runs/tmp/librarian-<timestamp>.patch`. Initial use cases:
-research-note drafts for promotable archive entries, MEMORY.md drift
-fixups, duplicate-doc merge proposals.
+Smoke-test `librarian_promote.py` against one real archive entry
+(`docs/archive/option-a-bench-result-2026-05-07.md` is a good
+candidate — durable architecture content). Run with the default
+claude backend, review the draft, and either accept it as
+`docs/research/option-a-bench-result.md` or note specific
+edit-distance from what we'd want. The result drives whether the
+prompt template needs tightening before adding survey mode.

scripts/librarian-ignore.txt

@@ -18,3 +18,8 @@ scripts/run_model_size_experiment.sh
 
 # Future config described in docs/plans/torch_compile.md
 configs/deep_cfr/default_compile.yaml
+
+# Hypothetical accept target named in docs/plans/librarian.md as a
+# smoke-test illustration; resolves naturally if Stage 2 promote is
+# accepted, otherwise stays a forward reference.
+docs/research/option-a-bench-result.md

scripts/librarian_promote.py

@@ -0,0 +1,168 @@
+"""Stage 2 LLM dispatcher: draft a research note from an archive entry.
+
+Reads `docs/archive/<name>.md`, assembles a prompt by stitching
+`scripts/librarian-prompt.md` (the system prompt) onto the archive
+body, and dispatches to the LLM CLI selected by the LIBRARIAN_LLM
+environment variable. The LLM's stdout is captured to
+`runs/tmp/librarian-promote-<timestamp>-draft.md`. The dispatcher
+never writes into `docs/research/` directly — the operator reviews
+the draft and copies/edits it themselves.
+
+Backends:
+    LIBRARIAN_LLM=claude   (default; invokes `claude -p`)
+    LIBRARIAN_LLM=codex    (invokes `codex exec`)
+    LIBRARIAN_LLM=gemini   (invokes `gemini -p`)
+
+Usage:
+    uv run python scripts/librarian_promote.py docs/archive/foo.md
+    uv run python scripts/librarian_promote.py docs/archive/foo.md --show-prompt
+    LIBRARIAN_LLM=codex uv run python scripts/librarian_promote.py docs/archive/foo.md
+"""
+
+from __future__ import annotations
+
+import argparse
+import os
+import re
+import subprocess
+import sys
+from datetime import datetime
+from pathlib import Path
+
+LLM_COMMANDS = {
+    "claude": ["claude", "-p"],
+    "codex": ["codex", "exec"],
+    "gemini": ["gemini", "-p"],
+}
+
+DATE_SUFFIX = re.compile(r"-\d{4}-\d{2}-\d{2}$")
+
+
+def _repo_root() -> Path:
+    current = Path(__file__).resolve()
+    for parent in current.parents:
+        if (parent / "pyproject.toml").is_file():
+            return parent
+    raise RuntimeError("pyproject.toml을 찾을 수 없어 repository root를 판정할 수 없습니다.")
+
+
+def _assemble_prompt(
+    system_prompt: str,
+    rel_archive: Path,
+    archive_body: str,
+    rel_target: Path,
+) -> str:
+    return (
+        f"{system_prompt}\n\n"
+        "---\n\n"
+        "Task: Draft a `docs/research/` note from the archive entry below.\n"
+        "Follow the rules in your system prompt above (style template, "
+        "`Last verified:` and `Source:` headers, `file:line` citations "
+        "verified against the current tree, ~1 page, prose over bullet "
+        "soup).\n\n"
+        f"**Source archive:** `{rel_archive}`\n"
+        f"**Suggested target filename:** `{rel_target}`\n\n"
+        "If the archive does not contain a durable conclusion (e.g. it "
+        "is a one-off bench result with no general lesson), respond "
+        "with a single line `SKIP: <reason>` instead of a draft.\n\n"
+        "Output: the markdown content of the new file only. No "
+        "preamble, no code fences around the whole thing, no "
+        "explanation after. Begin with the H1 header line.\n\n"
+        "---\n\n"
+        "Archive body:\n\n"
+        f"{archive_body}\n"
+    )
+
+
+def main() -> int:
+    parser = argparse.ArgumentParser(description=__doc__.splitlines()[0])
+    parser.add_argument(
+        "archive_path",
+        help="Path to a docs/archive/*.md entry to promote.",
+    )
+    parser.add_argument(
+        "--show-prompt",
+        action="store_true",
+        help="Print the assembled prompt to stdout and exit; do not call the LLM.",
+    )
+    args = parser.parse_args()
+
+    root = _repo_root()
+    archive = (root / args.archive_path).resolve()
+
+    if not archive.is_file():
+        print(f"Archive not found: {args.archive_path}", file=sys.stderr)
+        return 1
+    try:
+        rel_archive = archive.relative_to(root)
+    except ValueError:
+        print(f"Archive must live under repo root: {archive}", file=sys.stderr)
+        return 1
+    if not str(rel_archive).startswith("docs/archive/"):
+        print(
+            f"Refusing: archive must live under docs/archive/: {rel_archive}",
+            file=sys.stderr,
+        )
+        return 1
+
+    stem = DATE_SUFFIX.sub("", archive.stem)
+    target = root / "docs" / "research" / f"{stem}.md"
+    rel_target = target.relative_to(root)
+
+    if target.exists():
+        print(
+            f"Refusing: research counterpart already exists: {rel_target}",
+            file=sys.stderr,
+        )
+        return 1
+
+    system_prompt = (root / "scripts" / "librarian-prompt.md").read_text(encoding="utf-8")
+    archive_body = archive.read_text(encoding="utf-8")
+    prompt = _assemble_prompt(system_prompt, rel_archive, archive_body, rel_target)
+
+    if args.show_prompt:
+        sys.stdout.write(prompt)
+        return 0
+
+    backend = os.environ.get("LIBRARIAN_LLM", "claude").lower()
+    cmd = LLM_COMMANDS.get(backend)
+    if cmd is None:
+        print(
+            f"Unknown LIBRARIAN_LLM={backend}; supported: {sorted(LLM_COMMANDS)}",
+            file=sys.stderr,
+        )
+        return 1
+
+    timestamp = datetime.now().strftime("%Y-%m-%d_%H%M%S")
+    out_dir = root / "runs" / "tmp"
+    out_dir.mkdir(parents=True, exist_ok=True)
+    prompt_path = out_dir / f"librarian-promote-{timestamp}-prompt.md"
+    draft_path = out_dir / f"librarian-promote-{timestamp}-draft.md"
+    prompt_path.write_text(prompt, encoding="utf-8")
+
+    print(
+        f"Dispatching to {backend} (prompt saved to {prompt_path.relative_to(root)})",
+        file=sys.stderr,
+    )
+    result = subprocess.run(
+        cmd + [prompt],
+        capture_output=True,
+        text=True,
+        check=False,
+    )
+    if result.returncode != 0:
+        print(f"LLM call failed (exit {result.returncode}):", file=sys.stderr)
+        print(result.stderr, file=sys.stderr)
+        return result.returncode
+
+    draft_path.write_text(result.stdout, encoding="utf-8")
+    print(f"Draft written to: {draft_path.relative_to(root)}")
+    print(f"Suggested target on accept: {rel_target}")
+    print()
+    print("Next: review the draft. To accept verbatim:")
+    print(f"  cp {draft_path.relative_to(root)} {rel_target}")
+    return 0
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())