feat(RMGR-WP-0001): complete T05 end-to-end vertical slice

Implement observe/reconcile/update-task-status CLI path: workplan parse,
JSON projection index, git-backed task status writeback with correlation
events, and E2E pytest plus evidence artifacts. Finish foundation workplan.

src/repo_manager/parse/__init__.py

@@ -0,0 +1,3 @@
+from repo_manager.parse.workplan import ParsedTask, ParsedWorkplan, parse_workplan_file
+
+__all__ = ["ParsedTask", "ParsedWorkplan", "parse_workplan_file"]

src/repo_manager/parse/workplan.py

@@ -0,0 +1,114 @@
+"""Workplan file parser (P0 extract — simplified from State Hub consistency_check)."""
+
+from __future__ import annotations
+
+import re
+from dataclasses import dataclass, field
+from pathlib import Path
+from typing import Any
+
+import yaml
+
+_TASK_BLOCK_RE = re.compile(r"```task\s*\n(.*?)\n```", re.DOTALL)
+_HEADING_RE = re.compile(r"^(#{1,6})\s+(.+)$", re.MULTILINE)
+
+
+def _parse_yaml_block(raw: str) -> dict[str, Any]:
+    try:
+        data = yaml.safe_load(raw) or {}
+    except yaml.YAMLError:
+        return {}
+    return data if isinstance(data, dict) else {}
+
+
+def parse_frontmatter(text: str) -> tuple[dict[str, Any], str]:
+    if not text.startswith("---"):
+        return {}, text
+    parts = text.split("---", 2)
+    if len(parts) < 3:
+        return {}, text
+    return _parse_yaml_block(parts[1].strip()), parts[2]
+
+
+@dataclass
+class ParsedTask:
+    id: str | None
+    title: str | None
+    status: str | None
+    state_hub_task_id: str | None
+    raw: dict[str, Any] = field(default_factory=dict)
+
+
+@dataclass
+class ParsedWorkplan:
+    path: str
+    id: str | None
+    title: str | None
+    status: str | None
+    state_hub_workstream_id: str | None
+    frontmatter: dict[str, Any]
+    tasks: list[ParsedTask]
+
+
+def parse_task_blocks(body: str) -> list[ParsedTask]:
+    headings = [
+        (m.start(), len(m.group(1)), m.group(2).strip())
+        for m in _HEADING_RE.finditer(body)
+    ]
+    results: list[ParsedTask] = []
+    for m in _TASK_BLOCK_RE.finditer(body):
+        meta = _parse_yaml_block(m.group(1).strip())
+        prev = [(pos, level, text) for pos, level, text in headings if pos < m.start()]
+        title = meta.get("title")
+        if not title and prev:
+            title = prev[-1][2]
+        results.append(
+            ParsedTask(
+                id=str(meta["id"]) if meta.get("id") is not None else None,
+                title=str(title) if title else None,
+                status=str(meta["status"]) if meta.get("status") is not None else None,
+                state_hub_task_id=(
+                    str(meta["state_hub_task_id"]).strip().strip('"')
+                    if meta.get("state_hub_task_id") is not None
+                    else None
+                ),
+                raw=meta,
+            )
+        )
+    return results
+
+
+def parse_workplan_text(text: str, *, relative_path: str) -> ParsedWorkplan:
+    fm, body = parse_frontmatter(text)
+    return ParsedWorkplan(
+        path=relative_path,
+        id=str(fm["id"]) if fm.get("id") is not None else None,
+        title=str(fm["title"]) if fm.get("title") is not None else None,
+        status=str(fm["status"]) if fm.get("status") is not None else None,
+        state_hub_workstream_id=(
+            str(fm["state_hub_workstream_id"]).strip().strip('"')
+            if fm.get("state_hub_workstream_id") is not None
+            else None
+        ),
+        frontmatter=fm,
+        tasks=parse_task_blocks(body),
+    )
+
+
+def parse_workplan_file(path: Path, *, repo_root: Path) -> ParsedWorkplan:
+    text = path.read_text(encoding="utf-8")
+    rel = str(path.relative_to(repo_root))
+    return parse_workplan_text(text, relative_path=rel)
+
+
+def iter_workplan_files(repo_root: Path) -> list[Path]:
+    wp_dir = repo_root / "workplans"
+    if not wp_dir.is_dir():
+        return []
+    files: list[Path] = []
+    for p in sorted(wp_dir.rglob("*.md")):
+        if p.name.startswith("."):
+            continue
+        # skip archived copies optionally still include them
+        files.append(p)
+    return files