feat(409): the reporting-back skill shapes the reply the operator reads (#4011)

Step 2 of milestone 409 "Response shapes". A reply written in the order the
work happened is accurate and still unreadable to someone who was not there.
The new bundled skill shapes it around where the work stands.

- Fires when an agent is about to report completion, hand off, ask the
  operator something, answer "where are we", or propose an approach.
- Every reply: conclusion first, one topic per section, visible priority,
  the ask in bold at the end, plain words, the work placed in Scribe.
- Placement is taken from the placement block step 1 returns (#4010), not
  recalled; untracked work is said to be untracked.
- Four families of shapes: Reports, Asks, Answers, Proposals, with the
  completion report written out in full.
- Domain-neutral: the worked example is a backup job, evidence is "what you
  could open to check it". Written as practices, and naming no instance rule.
- A structural guard pins the completion sections, the from-the-record
  placement, and the absence of software-only vocabulary.

Listed in the plugin README and manifest description; version minted.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

tests/test_reporting_back_skill.py

@@ -0,0 +1,55 @@
+"""The reporting-back skill keeps its shape (milestone 409 step 2).
+
+WHY THIS EXISTS
+
+The skill is what turns a reply written in the order the work happened into
+one the operator can read: where the work sits, what changed, what needs
+them, what is next. Its value is in its SECTIONS, and a later tidy-up that
+folds them into prose would leave a skill that still loads and no longer
+shapes anything.
+
+WHAT THIS PINS, AND WHAT IT DOES NOT
+
+Structure, never wording — the same reason test_create_tools_disambiguate
+gives: a test that punishes rewriting gets deleted. It pins that the
+completion report keeps its five sections, that placement is taken from the
+record rather than recalled, and that the shipped shapes stay domain-neutral.
+Whether the guidance is any good is milestone 409's last step, read against
+real replies, not something a test can see.
+"""
+import pathlib
+import re
+
+SKILL = pathlib.Path(__file__).resolve().parents[1] / "plugin/skills/reporting-back/SKILL.md"
+
+
+def _text() -> str:
+    return " ".join(SKILL.read_text().split())
+
+
+def test_the_skill_names_itself_as_its_directory():
+    front = re.search(r"^---\s*\nname:\s*(\S+)", SKILL.read_text())
+    assert front and front.group(1) == "reporting-back"
+
+
+def test_the_completion_report_keeps_its_sections():
+    text = _text()
+    for section in ("Where this sits", "What now works", "How / why", "Needs you", "Next"):
+        assert section in text, f"the completion report lost its {section!r} section"
+
+
+def test_placement_comes_from_the_record():
+    """The failure this milestone started from: a placement written from memory
+    reads exactly like a real one when it is wrong."""
+    text = _text().lower()
+    assert "placement" in text and "take the placement from the record" in text
+
+
+def test_the_shipped_shapes_assume_no_particular_domain():
+    """Scribe is domain-neutral: a home-infrastructure or writing project reads
+    these too. Software-specific evidence belongs in an operator's own
+    preferences, never in the product default."""
+    text = _text()
+    dev_only = [w for w in (r"\bCI\b", r"\bcommit", r"\bpull request", r"file:line", r"\bpytest\b")
+                if re.search(w, text, re.IGNORECASE)]
+    assert not dev_only, f"software-only vocabulary in a product-wide shape: {dev_only}"